"We will know later how bad it is but the early signs are he will not be able to perform for us the next four weeks. "It is a big blow. I hope he will be back soon and we'll do the maximum to get him back," manager Arsene Wenger told the club's official website.
Arsenal have also found out today that their Swiss defender Phillipe Senderos is likely to be out for two weeks after picking up a back injury during his sides friendly match against USA last night. Obviously both injuries are terrible news for Arsenal because both players have played very well this season and they will be missed.
Both players are likely to miss their sides games against Bolton, Liverpool and Manchester United, all of which are very tricky ties. I can see Eduardo maybe getting a run in the first team now and it will be interesting to see how he adapts to the Premier League because as of yet he has failed to make a lasting impression in the brief spells he has had.