We must learn lessons - Vermaelen

The Gunners were thumped 4-0 by a well-drilled AC Milan side in the first leg of their Champions League last-16 tie, which all but put paid to any hopes of progress.

"We will have to learn our lessons from what happened in Milan, but it is important at times like this to remain mentally strong and focus on the next game," Vermaelen said.

Arsenal manager Arsene Wenger has challenged his team to regroup and deliver a performance when they head back to the Stadium of Light for Saturday's late kick-off a week after their 2-1 win lifted them into the top four of the Barclays Premier League.

A place in the quarter-finals of the FA Cup - which is now the only trophy Arsenal have a realistic chance of winning - would certainly be a welcome tonic and renew belief.

"When you are a professional you put the bad things that happen behind you," Vermaelen said.

Arsenal were never in the contest on Wednesday night, failing to get to grips with Milan's rampaging front three of Kevin-Prince Boateng, Robinho and Zlatan Ibrahimovic, who all got on the scoresheet. Robin van Persie had the Gunners' best of their limited chances on 65 minutes, but saw his fine volley saved at full stretch Christian Abbiati.

With no away goal to give some hope of an unlikely comeback, Wenger admitted Arsenal were now all but out of the competition. While the second leg at the Emirates Stadium in a fortnight is almost redundant, Vermaelen, 26, insists the players owe it to the Gunners' fans to produce a performance.

"The only thing we can do is remember that we've still got another game to go. Now we have to show some pride and give 100% in the return leg," Vermaelen said. "We have to give something back to all those Arsenal fans who came all the way out here to this stadium, here in Milan, only for us to disappoint them.

"We must think of them now because what happened was not good. The only thing we can do is give them a good result in the home game."