Chelsea defender Gary Cahill believes the busy fixture schedule is taking its toll on him and his team-mates as the club compete on three fronts this season.
Alongside their push for a top-four Premier League finish, Rafael Benitez's men are also competing in the FA Cup and UEFA Europa League.
After next week's international break, Chelsea will take in a run of six games in 16 days, including a two-legged Europa League quarter-final and the replay of their FA Cup last-eight tie with Manchester United.
While reluctant to make excuses for the Blues' inconsistent form this season, 27-year-old centre-half Cahill admits the congested fixture list is proving tough.
He told the Daily Telegraph: "People criticise you if you say you are tired, and we know we have to get on with it because the fixtures are there.
"But all I am saying, as a general fact, is that players do not go into every game feeling 100 per cent fresh, it is impossible.
"At a big club every single game is so important, but you might be going in 60-70 per cent fresh through no fault of your own.
"Everyone is trying to recover but you just don't have the days. It is not an excuse, but it is a fact."
Competition
Cahill, who joined Chelsea from Bolton in January 2012, has notched up 38 appearances for the club in all competitions so far this season and has missed just one Premier League game this year.
Despite cementing his place as a first-team regular under Benitez, the England international is taking nothing for granted with the likes of John Terry and David Luiz also competing for the centre-half berth.
He said: "The main thing is that I am playing in a lot of the big games, I am playing more regularly now, but we have got the luxury of four centre-backs now so we can chop and change.
"I think maybe I proved when I first came that I could play in the Champions League, because we went on and won it, and I played the games in there. Playing with England has helped me as well.
"You come here from a smaller club and people wonder, can he play here, can he do this? And you always feel like you are trying to prove yourself to people all the time. For me now it is just trying to prove that I can maintain a starting place at Chelsea."
Fellaini was booed off by fans when he was replaced during Everton's shock FA Cup quarter-final defeat last weekend, with supporters unhappy with the Belgian's attitude.
An appearance at an official Everton store earlier this week was postponed and Moyes accepts Fellaini's stock may have fallen with the fans.
However, Moyes is prepared to give the 25-year-old a chance to make amends when Everton face Premier League champions Manchester City at Goodison Park on Saturday.
"His reaction wasn't right, it wasn't the correct one and I have told him that," said the Everton manager.
"He knows that he should have played much better, and yes, he may have some making up to do with the fans, but I won't have any trouble picking him.
"I'll play Marouane against Man City as I have to give us the best chance of winning. That means picking our best players and giving them a chance to make amends.
"Don't forget the good stuff he's done. For the most part he's been outstanding and made a huge contribution.
"Most of the lads had a disappointing day, even if he found it tougher than most.
"He may not be firing as he might, but he's still been influential for us. He is the only player I'm talking about, but there were eight others we could be talking about."
Allardyce's current deal expires at the end of the season and co-chairman David Gold recently stated that talks over an extension would be held in the summer.
However, Allardyce is keen to start planning for next season and sees no reason to wait until the campaign is over to hold negotiations, if the Hammers are safe.
"We'll sit down when we're safe," said Allardyce. "What's the point me waiting until the end of the season if we're mathematically safe with a few games to go?
"There's no point in that is there? We need to start budgeting."
West Ham are currently 12th in the table with 33 points, nine points clear of the relegation zone, and Allardyce feels 38 points will be enough to preserve the club's top-flight status.
He added: "I think we need another five points. Thirty eight will make you safe this year but we will all aim for 40 just in case.
"Hopefully we will be safe as soon as possible because there is a lot to negotiate and a lot to move on, which we are doing."
The left-back made the game safe after a brace from the mercurial Lionel Messi and a goal from David Villa helped the Catalan club overturn a 2-0 deficit from the first leg of their last-16 tie.
Milan's success at the San Siro left many criticising some of Barcelona's stars for failing to produce the goods on Europe's grandest stage.
But their emphatic 4-0 triumph at the Nou Camp answered many questions, with Alba urging his side to continue that form into the weekend when they return to Primera Division action at home against Rayo Vallecano on Sunday.
"Outside of the club there was a lot of doubt, but we were all calm," he told a press conference.
"We weren't playing badly in these three games against Milan and Real Madrid but we just lacked the same intensity and aggression. The other day we saw the real Barcelona and now we have to maintain this level.
"We have to continue this level of play and aggression until the end of the season."
Of his goal, Alba added: "It was one of the most important goals of my career because it sealed the win after we'd suffered a lot in the last 10 minutes".
While much focus centred on Friday's Champions League draw, with Barca paired with Paris St Germain in the last eight, Alba is very well aware they can not afford to take their eyes off the challenge posed by Vallecano.
Barca are 13 points clear at the top of La Liga, but Alba insists the players are not content to rest on their laurels against a Vallecano side that lie eighth in the table but have won just four of 13 league matches on their travels.
"We have to try and win the league as soon as possible," he said.
"Rayo are having a magnificent season. They like to play with the ball and they are aggressive without it. I like the way they play."
Stand-in head coach Jordi Roura is likely to be without midfielder Xavi, who suffered an injured thigh against Milan, while goalkeeper Victor Valdes will sit out due to suspension.
Messi hit his 52nd and 53rd goals of the season on Tuesday, but Vallecano midfielder Roberto Trashorras says the side have not decided on a specific way to derail the Argentinian.
"We have not spoken especially about Messi," the former Barca man told Vallecano's official website.
"We have talked about how to disrupt their rhythm and we intend to complicate the game for Barcelona."
Defender Jose Manuel Casado, midfielder Javi Fuego and striker Leo Baptistao will be unavailable for the trip to the Nou Camp against a club goalkeeper David Cobeno says Vallecano need to be at their very best to beat.
"Of course we will be motivated against Barca," he said.
"We're playing against one of the best teams in the world in a week where they have played and won a very important game.
"They will be very motivated and we have to try to do what we've done all year: to enjoy and look for something positive.
"Even when they are at 80 per cent they are better than other teams. We have to be at 120 per cent in order to get something and if they are lower because they are more relaxed, so much the better for us."
In a further bizarre twist to Palermo's troubled season, Sannino returned to the Stadio Renzo Barbera this week - six months after being sacked just three games into the current campaign.
The Neapolitan was first replaced by Gian Piero Gasperini, who made way for Alberto Malesani for 19 days before ending his brief return to Sicily by mutual consent on Monday.
Palermo now have 10 games to overturn a five-point gap on 17th-placed Genoa and prolong their nine-season stint in the top flight, with Sannino urging a dignified approach to a tricky run-in.
He told La Repubblica: "I don't want to create expectations or make predictions - that's not what the people of Palermo need to hear.
"Enough worrying about the league table - all that matters is what we have inside us.
"Looking at our place in the league table, Palermo just need to shut up talking about what hasn't been done and focus on what needs to be done.
"My task is to bring the season to a close with dignity and with the utmost respect for the fans and the club."
Edgar Barreto is doubtful to feature at San Siro, with Abel Hernandez and Andrea Mantovani definitely sidelined through injury.
"We have to work out what we need to do in these last 10 games, without forgetting about the daily work we're doing in training or in each individual match," Sannino added.
"It will be a 10-game championship and we will worry about the numbers at the end of it.
"You can only admit you're dead when your body is cold, but mine is still warm and I hope the same of my players. We will need heart, desire and sacrifice."
Milan, meanwhile, are eager to offset a disappointing week and heap further misery on Palermo with a victory to boost their chances of reaching second place.
The Rossoneri were tasked with protecting a two-goal lead at Barcelona in the Champions League on Tuesday but a Lionel Messi-led comeback saw Massimiliano Allegri's men beaten 4-2 on aggregate.
The nature of the defeat might have been galling, but Allegri predicts better times ahead for his rejuvenated squad.
"Sunday is another game and we shouldn't look back," Allegri told acmilan.com. "Given the young age of the squad that we have now, there'll be time to get to another Champions League semi-final or even the final."
Mario Balotelli returns to contention, with both fellow striker Giampaolo Pazzini and midfielder Nigel De Jong nursing leg injuries as Kevin Constant serves a one-match suspension.
O'Neill has called up 24 players for the Group F qualifier against Russia on Friday, with Kyle Lafferty and Chris Baird joining the squad for the game against Israel four days later after serving one-game bans.
In total, O'Neill's squad calls upon players from eight different divisions across England, Scotland, Greece and Switzerland, but he knows he cannot afford any of them to pick up injuries over the weekend.
Only Dean Shiels, of Rangers, is currently unfit for selection and, with three points from the first four games of the campaign, O'Neill does not want to any more withdrawals.
"I have pretty much everyone I want now and I just hope they come through the weekend unscathed," he told Press Association Sport.
"Most of our lads play today, which is good in terms of us getting them for a bit of work next week.
"But the main hope is not to lose any more players because we know our resources are limited, especially going up against this level of opposition."
One man who has been on the wrong end of numerous injury problems in Burnley striker Martin Paterson.
But O'Neill was glad to name him in yesterday's squad after the 25-year-old opted to end a self-imposed international absence, taken with the intention of getting himself back to peak fitness.
"At the time, Martin was in a difficult place injury-wise with his club and he's had a lot of problems in the last 12 months," O'Neill explained.
"In light of that he just felt at the time he needed to concentrate on his fitness and get a run of games together.
"He felt being involved at international level would not help and I understood that. I wanted to have him involved but he felt it was better to take himself out.
"We kept the dialogue open and I spoke to Martin soon after Christmas when he'd played for the best part of three months injury-free and he is happy to come back."
Paterson, who scored his first international goal from the penalty spot in his last appearance against Finland, still faces competition for a starting spot though.
Will Grigg has scored seven times in his last four matches, albeit in npower League One with Walsall, Billy McKay and Niall McGinn are enjoying prolific seasons in Scotland, and Jamie Ward has scored 11 times for Derby this term.
However, McKay, Grigg and Ward have just seven caps between them and McGinn has been used exclusively as a winger by O'Neill, leaving Paterson with a big chance.
"Martin is obviously a bit more experienced than the other options like William or McKay.
"They are both doing extremely well but are relatively inexperienced at international level. Martin has experience of the Championship and the Premier League and although he hasn't played as much internationally as we'd like, partly because of his injuries, he's certainly a nice option to have.
"Kyle's ban is an opportunity for someone to state their case."
Whilst Rio Ferdinand's inclusion in the Three Lions squad to face San Marino and Montenegro later this month grabbed all the attention, the fact Baines' presence merited no discussion underlined the giant strides he has made.
The Everton defender has started five out of seven England games so far this season and was a half-time substitute in one of the others. Indeed, there are some who feel Baines is actually a better bet than Ashley Cole, who reached his century of caps against Brazil last month.
Baines is too diplomatic to get involved in any discussion like that.
However, speaking on a tour of the Ellesmere Port car plant of England team sponsors Vauxhall, Baines said: "It has been a positive 12 months for me.
"I have been involved more and got more game time. I am in as good a place as I have been in international football.
"I was 25 when I first came into the England squad.
"Maybe it took me a bit of time to accumulate any experience, or get any kind of caps just because there is such a good player in the same position as me.
"But I just try and do my own thing. The rest is down to the manager."
Whilst it is undeniable that the crucial aspect of the Three Lions' latest engagement - their trip to Group H leaders Montenegro on March 26 - will mean nothing if England do not beat San Marino in Serravalle on Friday, the chances of that happening are virtually nil.
After all, San Marino's only victory came in a friendly against Liechtenstein in 2004, and when they came to Wembley in October, a country with a population of less than 32,000 managed just a single shot.
"It is strange because you really don't get any games like that in the Premier League," said Baines.
"Their objective is to stay in the game for as long as they can and sometimes it is not quite as simple as you think because they stick so many bodies behind the ball.
"If you don't score after about 20 minutes you might be tempted to force things. If they don't come off, you can get a bit anxious.
"An early goal always helps but you like to think, over the course of 90 minutes, with the players we have, we can get the job done."
The Japanese player has made just seven appearances for the Latics in an injury-dogged season which could have been ended by an ankle injury in last weekend's FA Cup quarter-final win at Everton.
Miyaichi requires surgery to repair the ligament damage and it may rule him out of Wigan's remaining games.
But Martinez is a huge fan of the 20-year-old and would be keen to extend their working relationship if Gunners boss Arsene Wenger will allow it.
"We will have to speak with Arsenal and we need to assess and make sure they are happy with the progression of the player," said the Latics boss.
"Ryo is a footballer that we really admire and has an incredible future in front of him so if we could work with him for a longer period we would be very happy to do that."
Wigan have had their fair share of injuries this season, critically to players like centre-back Antolin Alcaraz who has made just six appearances, having been sidelined for nearly six months with a groin problem.
Martinez believes he has noticed an upward trend in injuries among all clubs and has an interesting theory as to a contributing factor.
"Don't get me wrong, football in general gets more demanding physically, that is clearly the way the game is developing," he said.
"The more technology in sports science means you create better athletes but I think the weather and rain we had this summer has created difficult surfaces to play and train on.
"It would be interesting to find out how many injuries clubs throughout the leagues have had compared to last year because the number has been much higher.
"I don't think the physicality of the league has anything to do with that."
Martinez, preparing his side for the visit of Newcastle tomorrow, believes this year's relegation fight is the toughest he has experienced.
"The teams in the bottom three I don't think are going to stay there: there will be other teams involved and it will go down to the final day once more," said the Latics boss, whose side dropped into the relegation zone because of their FA Cup involvement last weekend.
"Year after year that fight becomes harder because teams are more prepared and stronger to cope with the demands in that final push.
"I do see it as the strongest fight out of the last four I've been involved."
Mancini wishes he had moved to bolster his rearguard after captain Vincent Kompany was injured in the FA Cup fourth-round win at Stoke on January 26.
At the time City did not expect the 26-year-old's calf problem to require a lengthy lay-off but he has not played since and Mancini feels his absence has been a "big problem".
Despite Mancini stating on several occasions the Belgian is close to fitness, his return has continually been put back and he has now missed seven games.
He will not be risked for this weekend's trip to Everton and the next game against Newcastle in a fortnight, after the international break, is now being considered as the comeback target.
Mancini said: "Probably we made a mistake because when we knew (of) this problem we were four days to (the) close (of) the market.
"Probably then we should maybe have bought another defender.
"Also, last year he had this problem, for one month he didn't play. This is a big problem. For me we did a mistake in this case.
"We had a chance because we had one good defender but we didn't think that Vinny would stay out for 40-45 days."
City have also been without two other defenders in Micah Richards and Maicon through injury but their only major transfer activity in January saw striker Mario Balotelli leave the club.
Kompany's prolonged absence has raised fears he may require surgery or miss the rest of the season but Mancini continues to play down the seriousness.
He said: "He starts to run and we hope that he will be ready for Newcastle.
"He started with us three or four days ago but he was tired because he worked a lot.
"His calf was tired but he didn't have any problems.
"But we don't want to take a risk at this moment because we have one game and after it is the international break. It is better we wait."
Kompany's absence has seen Kolo Toure, fourth-choice centre-back earlier in the season, return to form and prominence with four successive starts.
With 19-year-old Matija Nastasic continuing to hold down a regular place, Joleon Lescott's appearances have remained infrequent.
Lescott was outstanding last season but his lack of game time this season was highlighted this week when he was overlooked for England selection.
Mancini said: "I love Joleon Lescott. Seriously, because Joleon is a top-quality man and a serious, serious professional player.
"He is perfect as a man and as a player. After I can decide if he stays on the bench but this is another story."
Mancini said the 30-year-old remains part of his plans and has continued to feature, if only off the bench.
He said: "You ask me about the national team? He didn't play one game in the last month. He always played."
Lescott made his first start in five games in the FA Cup quarter-final against Barnsley last weekend. In the three games between those starts he was actually an unused substitute twice but did feature once off the bench.
When asked if he could understand why he had been left out by England, Mancini said at a press conference: "I don't know.
"But I read all the newspapers pushed for Rio (Ferdinand).
"One manager should take a decision, he has a lot of defenders. I don't know but Joleon is a good player."
City face Lescott's old club Everton at Goodison Park this weekend needing to win to keep alive their slim hopes of retaining the Barclays Premier League title.
Mancini hopes David Moyes' men are still subdued after last weekend's shock FA Cup quarter-final loss to Wigan.
He said: "For them tomorrow will be important, for sure, because maybe they want to take Europa League.
City's 5-0 thrashing of Barnsley was their best performance of the season and Mancini agreed - "yes, I think so," he said - when asked if his team are getting stronger.
But with with a gap of 12 points at the top of the table, he still needs leaders Manchester United to tire.
He said: "Now, 10 games from the end, all the teams could be tired after eight months. We hope."
The Belgian centre-half was, along with goalkeeper Wojciech Szczesny, left out against Bayern Munich in midweek, but could return for Saturday's trip to Swansea.
Despite the importance traditionally placed on the armband within the English game, Wenger insists his skipper must sometimes be prepared to make way for the good of the team.
"In England, it is true the captain is a massive importance," said Wenger, whose previous Arsenal skippers were Tony Adams, Patrick Vieira, Thierry Henry, William Gallas, Cesc Fabregas and most recently Robin van Persie.
"But (the) one who is a captain and a leader, that shouldn't guarantee you a place in any game.
"For purely sporting reasons, or tactical reasons in the game when you don't think it is the right selection, do you put the player in just because he is captain? That is disrespectful to the guy who doesn't play.
"For sporting reasons it is not completely justifiable."
Wenger admits getting his central defensive pairing right this season has not proved as straightforward as he had hoped.
Per Mertesacker, so often the target of criticism, and Laurent Koscielny produced a solid display as the team secured a clean sheet in the Allianz Arena, albeit one which in the end was not enough for safe passage into the quarter-finals of the Champions League, with the Gunners ousted on away goals.
Wenger said: "They do well together - it is true, but I can't see any obvious reason why Per and Vermaelen should not do well together.
"Also in some big games, I have played Vermaelen and Koscielny together.
"You think that should work as well because they are two good football players, one is right-footed and one is left-footed, they compliment each other well.
"However, sometimes there are mysteries in our game that are difficult to rationalise."
Koscielny was a largely unknown quantity when he signed from Lorient in July 2010, but the 27-year-old is now an established France international and has impressed with some consistent displays, including at full-back, in what has at times been a shaky Arsenal rearguard.
Wenger said: "Koscielny has shown a bit more authority than usual and when he gets into that frame of mind, you can see he has the outstanding qualities.
"It is something I know he has, but he needs that authority in his game to get his qualities completely out."
Lukasz Fabianski, meanwhile, did his prospects of retaining the goalkeeper's jersey no harm with a solid performance against Bayern, making some telling saves in what was a first senior Arsenal appearance in more than a year.
Wenger feels the Poland international has come full circle since a string of errors - including a howler against Chelsea which gifted Didier Drogba the winning goal in the 2009 FA Cup semi-final at Wembley on his 24th birthday - saw him labelled 'Flappy Handski' by some supporters.
"He has top quality, Fabianski. He has gone through difficult times, but he faced it and handled it and he did something about it," said Wenger.
"He lacked a bit confidence, suffered a bit under pressure, but let us not forget that to mature helps as well, that is one of the advantages of ageing.
"I believe more as well that technical approach is very important, that you manage to focus on what is important in your game."
Fabianski, signed from Legia Warsaw in May 2007, was hampered by ankle and knee problems injury earlier in the season, which saw Italian Vito Mannone emerge as understudy to Szczesny, playing a dozen first-team games including in the Champions League.
There had been suggestions Fabianski, who was also number two under Manuel Almunia, would be allowed out on loan.
Wenger understands it is a difficult spell in the player's career.
"The problem for Fabianski is that he is 27, not 19. He is at an age where a goalkeeper needs to play, he wants to play," said Wenger.
"Every guy wants to play, but they want to play in big clubs as well where there is a lot of competition."
Riki's early goal settled the nerves inside the Riazor and the home fans had further reason for optimism just before the half-hour mark as Iago Aspas was sent off.
Silvio doubled the lead in the 64th minute as the league's bottom side looked to make their man advantage count and substitute Diogo Salomao, who had only come on a minute earlier, wrapped up the points in the 78th minute.
Park Chu-young pulled one back for Celta shortly after, but there was no sensational fightback.
Depor still have plenty of work to do to avoid the drop from the Primera Division, but the win at least took them to within three points of their opponents and six of safety.
It also ended a nine-match winless run in the league, seven of which have been losses.
Depor got off to the ideal start as Riki put them ahead after nine minutes, volleying into the top corner from Juan Carlos Valeron's ball in from the left.
Celta threatened when Mario Bermejo headed wide from Enrique de Lucas' corner, but they suffered another blow in the 29th minute.
Aspas saw red for a foul on Carlos Marchena, leaving the visitors a man light for the final hour.
The hosts looked to take advantage, Riki seeing a shot from the left of the area tipped round a post by Javi Varas.
But they could not relax, with Celta going close when Augusto Fernandez met a Danijel Pranjic free-kick, but sent his header wide.
Depor started the second half brightly and Riki shot weakly wide from inside the area before a minute later having another effort acrobatically saved by Varas.
And they got a brilliant second in the 64th minute, on-loan defender Silvio crashing home his first goal for the club from 30 yards.
It was almost three in the 75th minute, but Varas was again alert to keep out a Bruno Gama effort from close range.
A third goal did arrive three minutes later, though, as substitute Salomao fired home a low shot from Valeron's pass.
Park pulled one back for Celta two minutes after that, tapping home Michael Krohn-Delhi's cross, but it was too little too late.
