Arsenal must balance a need for goals while resolutely guarding against Manchester United's marauding counter-attacks if they are to knock the holders out of the Champions League on Tuesday.
Arsene Wenger's side need to inflict United's first defeat in 25 Champions League matches as the defending champions arrive at the Emirates Stadium looking to protect a 1-0 advantage in the semi-final tie.
The winners play Chelsea or Barcelona in the final in Rome on May 27 and United's cause will be boosted if defender Rio Ferdinand is fit after bruising ribs in Wednesday's match at Old Trafford.
Ferdinand missed the 2-0 win at Middlesbrough on Saturday as United closed in on an 18th English league title but his return would further tighten United bid to become the first club to retain the European Cup in the Champions League era.
GROIN STRAIN
Arsenal, meanwhile, who need to score at least twice to win, hope striker Robin van Persie will be fit to return following a groin strain which has sidelined him for four games.
Arsenal manager Arsene Wenger, deprived of the cup-tied Andrei Arhsavin and injured striker Eduardo, will hope that striker Emmanuel Adebayor returns to his plundering best.
"I am confident we can beat United by two clear goals because we are 90 minutes away from the final," Wenger said.
"These are special circumstances because if we go a goal ahead they will be under pressure, knowing that if they concede again they will be out."
Arsenal, who only have the Champions League trophy to aim at to avoid a fourth successive season without a trophy, rested eight players who started against United in a 3-0 win over Portsmouth which guaranteed fourth place and a place in the Champions League qualifying round.
TITANIC STRUGGLE
Tuesday's match is expected to be another titanic struggle between two of England's biggest clubs who have a 115-year rivalry.
Arsenal have not conceded a home goal in five Champions League matches this season, but they have never beaten an English side in European competition.
United have scored on all three occasions they have played at the Emirates and it is seven seasons since Arsenal have beaten United at home with a result good enough to send them through.
Arsenal have not lost at home for 24 Champions League matches since Chelsea won 2-1 at Highbury in 2004. One way or another, something has to give.
Possible teams:
Arsenal: 1-Manuel Almunia; 3-Bacary Sagna, 5-Kolo Toure, 18-Mikael Silvestre, 40-Kieran Gibbs; 2-Abou Diaby, 17-Alex Song; 14-Theo Walcott, 4-Cesc Fabregas, 8-Samir Nasri; 25-Emmanuel Adebayor.
Manchester United: 1-Edwin van der Sar; 22-John O'Shea, 5-Rio Ferdinand, 15-Nemanja Vidic, 3-Patrice Evra; 24-Darren Fletcher, 16-Michael Carrick, 8-Anderson; 7-Cristiano Ronaldo, 32-Carlos Tevez, 10-Wayne Rooney.
Referee: Roberto Rosetti (Italy)
