Robin van Persie will miss Arsenal's crucial Champions League clash against Barcelona next Tuesday after being ruled out for at least three weeks with a knee injury.
Van Persie, who was injured whilst scoring for Arsenal in their 2-1 defeat in the Carling Cup final on Sunday, was in good form having netted 11 times in his last 13 games, including the equaliser in the first leg of the Champions League last-16 tie with Barca, which the Gunners won 2-1.
Manager Arsene Wenger said: "Unfortunately, we had bad news on the scan and he will be out for the next three weeks for sure. It could be longer. The shortest delay we can imagine is three weeks [so] he is definitely out for Barcelona."
However, Wenger described Cesc Fabregas as a "possible'' for the Nou Camp trip after revealing he is making quick progress in his rehabilitation from a hamstring problem.
Wenger also had good news about Cameroon international Alex Song, who anchored the midfield against Barcelona at the Emirates.
"Song has a knee problem as well. From his scan we had good news, it is only blood from a kick on the outside of his knee. He has a good chance for Barcelona," Wenger told the club's official website.
Defender Laurent Koscielny, who is nursing a minor hamstring problem, will be fit for the trip to Spain but will be rested for Wednesday's FA Cup fifth-round replay against Leyton Orient.
"Koscielny has a tight hamstring," Wenger said. "There is a little bit of fatigue in there as well so we will give him a breather. Almunia needs games so he will play, but Wojciech is all right and will be on the bench.
"Diaby was not in the squad on Sunday. I was cautious with him. He has missed many games this season and I did not want to take a gamble with the intensity of a cup final. He will play tomorrow night."