Jose Mourinho has confirmed Thibaut Courtois requires surgery on a knee injury and will be out for "quite a long time."

Courtois is likely to be out 10 to 12 weeks.

Mourinho said at a news conference ahead of Saturday's meeting with Everton: "Courtois was injured in a training session with the goalkeepers and I cannot tell you much, but I can tell you that he needs surgery in his right knee.

"As a consequence of that he will be out for quite a long time. I cannot be at this moment more specific about the injury or the time he will be out."

Asmir Begovic, who signed for Chelsea from Stoke in the summer, is set to play for Courtois in his absence.