Arsenal striker Thierry Henry is struggling with a hamstring injury and unlikely to play again this year, his manager Arsene Wenger said on Tuesday.

"Thierry has started his rehabilitation," Wenger said on the club's Web site (www.arsenal.com). "He is still not completely free from his hamstring (injury) so he starts again.

Asked if the France forward was out until after Christmas, Wenger added: "Realistically, certainly yes. I would not want to set a time on it. We will take the needed time."

Henry's fitness has been in question since he played in a Premier League match at Fulham on November 29, which was his last appearance for almost a month.

"We hope we can slowly build him up and make him competitive again," said Wenger. "The neck problem is sorted out. He had a sciatic nerve problem and a hamstring problem. And (the hamstring) is the most troubling for him now."

Sixth-placed Arsenal visit Wigan Athletic in the Premier League on Wednesday with defender Kolo Toure back in the squad after a one-match ban ruled him out of Sunday's 1-1 draw at Chelsea.

"We have Kolo back," said Wenger. "But he's the only one from Sunday. (William) Gallas is still out, Henry is out but (Tomas) Rosicky looks very, very promising and has a small, small chance for the weekend. Gallas too, maybe."

France defender Gallas has struggled with a thigh injury and Czech midfielder Rosicky has had a hamstring problem.