AC Milan coach Massimiliano Allegri is wary of Arsenal's strength in attack as the Serie A champions bid to end their poor run against English clubs in the last 16 of the Champions League.

Milan has been eliminated at this same stage of the Champions League by English clubs in three of the past four seasons, with Arsenal beating the Italian champions 2-0 at the San Siro in 2008.

Arsenal certainly poses a threat up front, with the Premier League's top scorer Robin van Persie in frightening form. Thierry Henry, who scored in his final league game against Sunderland at the weekend, is also looking to give the fans a parting gift in what will be his last match in a relatively successful loan spell at Arsenal before he returns to the New York Red Bulls.

''We need to have a game of great intensity, and we can't give them chances to counterattack because that's their strength,'' Allegri said on Tuesday. ''Arsenal is playing very well lately and is very dangerous in attack. And one of Arsenal's best qualities is their speed, especially if they have room enough.

''Van Persie and Henry are very dangerous players, so we have to be aware of them, but it is the team of Arsenal as a whole that is the most dangerous.''

Milan defender Thiago Silva, however, singled out Henry as the one he and his teammates need to pay most attention to.

''Henry is incomparable,'' he said. ''Everywhere he has gone he has created history. We have to pay attention to Henry because every game he comes into he makes a difference, we have to pay attention to him because he's a great player.

''But if you talk only about one player, then tomorrow it might be another one (that makes the difference), so we have to pay attention to everyone.''

Milan lost 1-0 at home to Tottenham last year before being held to a goaless draw in the away leg and Allegri knows his team cannot afford to concede on Wednesday.

''We made mistakes in the second half at home last year, we need to try to eliminate them,'' Allegri added. ''We must not make mistakes in defense and try to play well in attack, knowing that it's two-legged, so we need to take that into account in our game.

''Last year we played two very good games and we definitely deserved to win the second leg and go through. I'm very confident we'll go through this time.''

Thiago Silva added: ''If you go wrong in home game then you're out.''

Milan heads into the Arsenal match in high spirits, having regained its position atop Serie A with a 2-1 victory at Udinese on Saturday, and with its lengthy list of absent players finally starting to relent.

Christian Abbiati, Alessandro Nesta, Kevin-Prince Boateng, Alexandre Pato, Mathieu Flamini and Mario Yepes have all returned to training and are likely to be available, while Sweden striker Zlatan Ibrahimovic is back from a domestic ban.

''It's very difficult to say if they'll play or not because they've only done two or three training sessions with the squad so we'll have to see,'' Allegri said.

''What's certain is that seeing as Boateng's been out for four weeks, he won't start from the beginning and that's the same for Pato. But to have them available is a good thing.''

Arsenal have come out on top in four of its past six visits to Italy and have happy memories of San Siro as, before the win over Milan, it also beat Inter Milan 5-1.

Henry struck a hat trick that day but the Gunners great claims the notion of a stunning swansong is not playing on his mind.

''I have not thought about it,'' Henry said. ''I just want to help Arsenal on the night. I am an Arsenal player for one more game. Milan is Milan. It is another type of game and it is never easy to win away in the Champions League.

''You can always do better, that is what I tell myself. We will see after the last game against Milan how (the loan spell) was for me.''

Arsenal will be without Per Mertesacker after the Germany defender damaged ankle ligaments at the weekend.