Arsene Wenger has conceded that his initial prognosis that Arsenal forward Robin van Persie will be out for three weeks could be optimistic.
Van Persie limped off during the Carling Cup final defeat to Birmingham City on Sunday, after injuring himself while scoring the Gunners' equaliser. Speaking after Arsenal's 5-0 FA Cup victory over Leyton Orient on Wednesday, Wenger admitted he is now targeting a return for the striker in the game against Blackburn Rovers at the start of next month.
"I am not a specialist but he overstretched his knee at the back when he made the volley [to score on Sunday]," said Wenger. "He got kicked or blocked by the defender and overstretched when he hit the ball. In fact we lost Van Persie after 30 minutes, we tried to keep him going in the second half but he was injured.
"It is a ligament at the back of the knee, a tear in the ligament. It is three to four weeks, I take the short delay because I am an optimist but it could be four. As well it is the international break during that period so whether it is three or four [weeks], for us it is the same.
"We have two weeks to play now and then there is a two-week break because of international games. We have to hope it is only four; he cannot play before the international break, that is for sure. Let's hope he can play after the international break."
The Frenchman concedes even that could be optimistic, however, with Van Persie's recovery difficult to predict.
"I listen to what the medical people say to me and you never know, he can have a setback," he said. "You can never guarantee."
Van Persie will therefore definitely miss forthcoming Premier League games against Sunderland and West Brom, as well as the crucial Champions League clash with Barcelona and an FA Cup meeting with Manchester United.