Almunia is crap; he lost us the last tie, so don't expect that he will play.
Sagna is suspended for the first leg, so Eboué will be in; Nasri is injured, so Arshavin will play.
Anyone worrying about him tracking back should take a look at the diving tackles he made in the last two matches; he’s recovering his form and he’s going to be immense.
Walcott has to be played on the wing, his pace will keep the right side covered and we need him to cover Eboué a lot.
Wilshire is a central midfielder, he would be wasted on the right; he's Denilson kind of player, though a better passer, faster and more determined then him.
Robin van Persie will be up front, but don’t be surprised to see Bendtner and/or Chamakh making an appearance too. If pushed into a corner then we’ll have to have height to attack Barca with long balls in.
Our most important player in the two ties will be Walcott. There is no doubting Barca will attack and attack a lot, but Walcott will be the fear that will not allow them to go to forward.
Koscielny is absolutely perfect for Barca's style. Kozzer isn’t strong, but he’s a one on one specialist and rarely gets beaten because he times his tackles immensely well and he’s very fast.
As for Wilshire, I expect him to boss the midfield and after Song strong arms them. Barca are in for a very tough time against a duo of Wilshire and Song; Barca like to keep the ball and play it fast and low like us.
But they have to get through the monster that is Song first and if they manage to do that then there is Wilshire to intercept and I haven’t even talked about Djourou, it will be fun to see him keep villa in his pocket.
Another point which will be different for Barca will be the approach with which Arsenal will go in this game. Other teams try to defend against Barca, but Arsenal will try to attack and will on the break very quickly.