Alex has already been absent from his teams last two Barclays Premier League fixtures against Fulham and Sunderland.

"Further to the Chelsea medical team's diagnosis, the Brazilian national team doctors agree that further investigation via arthroscopic surgery is required on the player's right knee. That will take place over the coming days. He is expected to be out for approximately six to eight weeks," says Chelses' websote/

John Terry is also out with injury. Club captain Terry is undergoing treatment to resolve a problem with a nerve in his leg.

Carlo Ancelotti is said to be devastated by the news.