Cardiff centre-back Ben Turner looks set for a return to the line-up as they welcome Brighton.
The former Coventry defender, 25, has missed the last two games for the Bluebirds, against Huddersfield and Bristol City, with an ankle injury.
He looks likely to replace young defender Ben Nugent who picked up a dead leg in Saturday's victory over the Robins.
Manager Malky Mackay has no other injury concerns as Cardiff look to extend their 11-point lead over third-place Watford.
Winger Craig Noone returned to the side for the first time in a month against Bristol City and he is expected to continue in the starting line-up when his former club arrive in South Wales.
And despite his side's comfortable position at the top of the table, Mackay knows Cardiff cannot get carried away.
He said: "It is a relentless and unforgiving league and one that will constantly bite you if you don't approach it in a respectful and correct manner.
"It is about us making sure we go out there and do our jobs. I talk to them about being business-like. They know exactly what they have to do."
Brighton could be boosted by the return of skipper Gordon Greer.
The centre-half has missed the last three matches with a hamstring injury but has returned to training and will be assessed prior to kick-off.
Midfielder Andy Crofts will miss out again with a hamstring problem but the Seagulls hope he will resume training later this week ahead of Saturday's visit of Burnley.
Ashley Barnes completes a three-match ban and fellow striker Will Hoskins faces a spell out after suffering a knee injury in the 1-1 draw with Blackburn last Tuesday night.
Craig Mackail-Smith is pushing for a recall in attack alongside January signing Leonardo Ulloa after dropping to the bench against Rovers.
Harris' offer, made public on Monday, comes after Portsmouth's administrators PKF confirmed earlier this month they were considering a bid he was fronting.
The Football League responded then by announcing the south coast club would be expelled if the Pompey Supporters' Trust - PKF's preferred bidder - was not successful.
Trust spokesman Colin Farmery said fans had no interest in Harris' offer, in which 15% of shares will be allocated free to a group made up of supporters who have donated funds to PST, season-ticket holders and hospitality clients.
Farmery said: "Why would we be interested in 15% when we are just about to take a 100% stake in the club?
"It is curious timing to say the least from Mr Harris with the Football League having made it quite clear that our bid is the only one that can be considered.
"Mr Harris seems to think he has still got a bid but he hasn't. Our bid is literally about dotting the i's and crossing the t's."
The Trust expect to move a step closer to acquiring the club on Thursday when a court hearing will set a final date for the valuation of Fratton Park to be heard, followed by a high court date at which the Trust expect to be given the right to take over the club.
The Football League were not available for comment on whether Harris's revised bid would change anything with regard to their previous expulsion threat.
City's hopes of retaining their Premier League title may appear slim but Aguero says they are determined to go down fighting.
Aguero and his team-mates produced the perfect response to their damaging - and dismal - surrender at Southampton just over a week ago by brushing aside Championship outfit Leeds in the FA Cup.
The Argentinian struck twice as City powered into a quarter-final tie against Barnsley with a 4-0 win at Eastlands.
Attention now switches back to the league with City trailing rivals Manchester United by 12 points, with 12 games remaining, ahead of Sunday's clash against third-placed Chelsea.
Aguero told City TV: "This helped us to do things well and give us confidence for the Chelsea game.
"It will be a good match, difficult, but obviously we need to go out and win.
"I think against Southampton none of us played well and it was a bad day for us all - an error which we hope not to repeat.
"We will try not to lose any more points in the league so we can keep all three points.
"I think we've played well and reached the next round. We need to continue like this."
City outclassed a Leeds side who continue to labour in pursuit of a play-off place in their own division.
The result did not seem in doubt after Yaya Toure combined with David Silva and Carlos Tevez before opening the scoring after just five minutes.
Aguero quickly added the second from the penalty spot after he was deemed to have been pulled back by Tom Lees and created the third for Tevez early in the second half.
Aguero wrapped up the win when he clipped a well-weighted ball from Silva beyond Jamie Ashdown and in off the post 16 minutes from time.
City might have had several more. Substitute Jack Rodwell went closest to adding to the tally when he headed against the bar.
The build-up to the game had been dominated by fresh speculation over manager Roberto Mancini's position in the light of the Southampton capitulation.
But City fans made clear their support for the Italian, who is now eyeing a repeat of the 2011 FA Cup success.
Aguero said: "It was a very good game for us. We are happy with the win and reaching the next round of the FA Cup.
"We played well - from the start we gave it our all. We had spoken about having to give our all in the first 15 minutes.
"The truth is we played a great game and we hope we can continue to do so constantly."
Aguero himself has had a frustrating second season at City, having been curtailed at times by knee and hamstring injuries, but now has 13 goals for the season and looked in fine form.
The 24-year-old, a club record ?38million signing two years ago, said: "Yes, I had a great game. The whole team played well though.
"The important thing was to win and we did. So now we will have a bit of calm and can concentrate on the Chelsea game.
"Yes, they were two good goals but the most important thing was they helped us to win. So I'm happy for the goals and for the win.
"I really like this cup, played as a single leg. Obviously if we maintain our concentration, I think we have a team that can reach the final."
Mancini, who made clear he was not fearing for his position prior to a game billed as vital for his future, intends to carry on fighting on both fronts.
He said: "I had a negative energy after Southampton but I am happy after this game.
"I wanted a response after Southampton and we played well. Now it is important we continue."
"We are a top team. If we lose an important game, we should continue to work hard. In football, it is never finished."
