Arsenal will have to cope with injuries and carry the momentum from last week's comeback draw against Barcelona to pull off a Champions League quarterfinal victory at the Camp Nou on Tuesday.
Barcelona coach Pep Guardiola and Arsenal manager Arsene Wenger will be forced to alter their starting lineups because of injuries and suspension.
Barcelona is without striker Zlatan Ibrahimovic and center backs Gerard Pique and Carles Puyol, while Arsenal is hurting even more with a handful of starters missing, including captain Cesc Fabregas and Andrei Arshavin.
Following the 2-2 draw in the first leg, Arsenal will need to go for victory since the European champions hold the away-goal advantage.
"The first game was very exciting. The second game promises to be even more because we need to score goals," Wenger said on Monday. "The key is in our performance and not in any speculation over who plays on the other side."
Both teams will take momentum from league wins on Saturday, with an under-strength Barcelona rolling over Athletic Bilbao 4-1 and Nicklas Bendtner's injury-time goal earning Arsenal a 1-0 win over Wolverhampton Wanderers.
Fabregas broke his leg scoring the equalizing penalty in the first leg, although the former Barcelona youth player would not have played in the return match anyway because of suspension. Arsenal is also without Arshavin (calf), William Gallas (calf) and Alex Song was ruled out on Monday with a groin injury that puts further strain on the defense.
Wenger said Samir Nasri will lead the offense, while Theo Walcott could play a big part after starting the Gunners' rally last time with a goal.
Although Guardiola lauded Walcott's qualities, he didn't think the England winger would be Arsenal's salvation.
"Walcott was not the determining factor. The determining factor was Almunia who stopped a thousand shots," Guardiola said. "If he hadn't made all of those saves we probably wouldn't be talking about things the way we are."
Wenger said possession will be key to reaching the semifinals.
"I think we have won everywhere in Europe at all the big clubs, I think the only place we haven't done it is here," the Frenchman said. "We have the opportunity and this club has the chance to grab opportunity and make history."
Goalkeeper Manuel Almunia should expect more of the same from Guardiola's charges, especially with the inexperienced defender Craig Eastmond or Mikael Silvestre likely to fill-in in defense with 35-year-old Sol Campbell a doubt because of a hamstring injury.
And Barcelona will have Andres Iniesta back in attack early from a leg injury after Guardiola included him the team list.
"We have to forget about the last performance against Arsenal. We have to play good again," the Catalan coach said. "We're going to try to be ourselves and to get the ball and I think Mr. Wenger thinks the same. The team that has the ball more is going to win."
Ibrahimovic, who scored both goals at Arsenal, tore a muscle in his right calf, while Pique hurt his leg, although he was already suspended for the game.
Rafael Marquez and Gabriel Milito, who hasn't started a Champions League match in nearly two years, are the most likely fill-ins, although midfielder Yaya Toure could play despite hurting his ankle against Athletic.
Barcelona does have Lionel Messi back to his scoring ways after the winger netted for the first time in four games on Saturday for his league-leading 26th goal and 35th overall.
Guardiola may lean toward Bojan Krkic in place of Ibrahimovic instead of Thierry Henry. Henry received renewed criticism over his lackluster campaign following his performance in last week's draw at Emirates Stadium, while Krkic scored two goals against Athletic.
"It's a great game, a nice game to enjoy," Krkic said. "I'd like to play. We'll see, right?"
Wenger defended former Arsenal player Henry, although he didn't quite know the extent to the France striker's problems this season.
"Just because he plays a little less it doesn't mean you're finished," Wenger said of his team's all-time leading scorer.
Barcelona's season may be on the line this week. It plays at Real Madrid on Saturday in a match that could determine the Spanish league winner with both clubs even on points at the top of the standings.
Still, Arsenal's task is enormous - Barcelona has outscored opponents 13-2 at the Camp Nou in four knockout round games under Guardiola, whose team thrives on pressure games.
"After wining six titles the people demand more," Guardiola said.
