"But he has a scan this afternoon and he is better today than he was last night.
"That is positive for a muscle problem. But we'll know much more about it on Friday morning."
Wenger added: "We also have (Emmanuel) Adebayor who has a little ankle problem. We'll see how he is tomorrow. I hope he'll be okay. But the time is so short between the games it is very difficult to make a decision the morning after a game.
"You don't know if it is a bruise or a little twist and the first 24 hours doesn't tell you a lot about that."