Milan have several injury problems; Antonio Cassano is a long term injury after suffering a stroke, while Kevin Prince-Boateng, Alexandre Pato and Alessandro Nesta may all return for the Rossoneri. The return of Boateng is key for Milan's midfield; he brings energy and industry that is needed if Milan are to disrupt Arsenal's passing game. Milan, of course, play a narrow 4-3-1-2, which should allow Arsenal to exploit the wide areas if they are able to work the ball into space. The presence of Boateng, though, may prevent that, as he presses very well. Mark van Bommel and Antonio Nocerino are the other key men of Milan's midfield; both should be fit, with Nocerino breaking runs from midfield likely to be a threat.
Arsenal will be without Per Mertesacker, which should see Thomas Vermaelen return to his favoured role at centre back. The replacement at left back, however, is more problematic. Kieran Gibbs is fit again, but hasn't played in over 4 months, and Arsene Wenger mentioned Gibbs perhaps needing a reserve game. The other obvious option is Francis Coquelin, who impressed at left back against Fulham. Coquelin, of course, is usually a central player, but can provide good supporting runs for Alex Oxlade-Chamberlain or Andrey Arshavin. He can also come into the middle if Arsenal need support at centre back or in the centre of midfield, letting Thomas Vermaelen, Laurent Koscielny and Bacary Sagna form a back 3. Coquelin is also more match fit than Gibbs, having played against Aston Villa and Blackburn in recent weeks. Making your second start in the Champions League at the San Siro may faze some, but Coquelin made his first two league starts against United and Tottenham, and impressed in both.
van Bommel will likely block Arsenal through the middle, so Arsenal must take advantage of space in the wide areas. Theo Walcott thrives when he's given space, and he'll look to find Robin van Persie with cutbacks if the Dutchman can get away from Milan's impressive centre back, Thiago Silva. On the left, either Andrey Arshavin or Alex Oxlade-Chamberlain will start. Oxlade-Chamberlain will give Arsenal better width, and it'd be disappointing to see Arshavin start. He does have quality, but that quality may be better from the bench if Arsenal are chasing a goal. Milan's pressing will make it difficult for Arsenal to get the ball to wide areas, but if they switch the ball quickly into wide areas, they can get Walcott and Oxlade-Chamberlain one on one, and have them provide for Robin van Persie. In what is likely to be his final Champions League game ever, Thierry Henry could come on, either to rest Robin van Persie, or give Arsenal 2 strikers if van Persie is tightly marked.
Predicted lineup: Szczesny; Coquelin, Vermaelen, Koscielny, Sagna; Song, Arteta, Ramsey; Oxlade-Chamberlain, van Persie, Walcott.
Prediction: Mathieu Flamini and Alex Song face off in the battle of the defensive midfielder, a battle that Song wins using his mohican skills. That allows Arsenal to score through Robin van Persie, but Zlatan Ibrahmovic picks up the ball from centre midfield and beats everyone to score. The battle of the ONE MAN TEAMs ends in a draw, but puts Arsenal in a very strong position in the second leg.