Samir Nasri has urged his Arsenal team-mates to go on the offensive against Barcelona, because they're "not the same team" when pressurised.
The Gunners head to the Camp Nou next Tuesday defending a 2-1 lead, having come from behind to seal an impressive Champions League victory in London.
The two sides met at the quarter-final stage last year, when Arsenal were thumped 4-1 in Barcelona after battling to a 2-2 draw in the opening encounter, but Nasri insists that history will not repeat itself as Arsene Wenger's team are more "macho" now.
"Barcelona are like Brazil," he said. "They don't like it when you put pressure on them and attack them. They want to play their game. If you put pressure on them, they're not the same team.
"Barcelona seemed much better last year because we've become more macho, both physically and psychologically. Some of the players are much better this year than before - Theo Walcott, Jack Wilshere, myself.
"We've all stepped up and become stronger and more macho. Players have stepped up and driven the team forward. We can compete with everyone now."
Nasri has also expressed doubt over the fitness levels of the Barca team, insisting that they have a tendency to wilt towards the end of matches. Both of Arsenal's goals in the first leg came in the final quarter, with Robin Van Persie scoring on 78 minutes and Andrei Arshavin finding the net six minutes later.
"We came back in the first leg because physically they dropped," Nasri said. "This is because the Spanish league is not the same as the Premier League. In England, there is an intensity that isn't there in Spain."
Arsenal will be without Van Persie and Walcott at the Camp Nou, but Wenger is hopeful that captain Cesc Fabregas will be fit.