Chelsea goalkeeper Thibaut Courtois could miss three months with serious knee injury

Chelsea's troubled start to their Premier League title defence suffered a fresh blow on Friday when it emerged that goalkeeper Thibaut Courtois will be sidelined for around three months after knee surgery.

Courtois tore the meniscus of his right knee in training and is likely to be out until December following the operation, which is reported to have taken place in Spain.

"Thibaut Courtois underwent surgery yesterday (Thursday) on an avulsion of the posterior corner and medial part of the internal meniscus of his right knee," a Chelsea statement read.

"The successful surgery consisted of a reattachment of the meniscus by suturing."

Courtois remains in good spirits despite the injury and vowed to return to action as soon as possible.

"Thank you everyone for the support and the good wishes! I will work hard to recover as soon as I can!" Courtois tweeted, alongside a picture of himself smiling in a hospital bed.

Courtois returned from international duty after playing in Belgium's 1-0 win over Cyprus last Sunday, only to suffer the injury on Wednesday during a goalkeeper-specific training session.

"Everybody came back well from the national teams but Courtois was injured in a training session and I cannot tell you much but I can tell you he needs surgery in his right knee and as a consequence he will be out for quite a long time," Chelsea manager Jose Mourinho had said earlier on Friday before the club's confirmation of the operation.

- Big blow -

Mourinho, however, expressed full faith in £8 million ($12.4 million, 11 million euros) signing Asmir Begovic to replace him.

"It's a big blow but you will not see me speaking again about Thibaut. He's injured.

"It's not easy to have the best goalkeeper in the world injured. But it's easy to have one of the best goalkeepers in the world to play.

"Begovic is very, very good. I'm sad for Thibaut and sad for the team but we have a top goalkeeper and Begovic will be in goal."

The injury only adds to Chelsea's concerns ahead of a trip to Goodison Park that is already underscored by flashpoints and controversies.

Mourinho's side have only four points from four games, the second worst start by a team defending the Premier League title, and face an Everton whose manager Roberto Martinez and owner Bill Kenwright have been so publicly critical of Chelsea's unsuccessful pursuit of 21-year-old defender John Stones.

Mourinho played all of that down, and insisted that his team's performances have been better than results have suggested.

"What Martinez says for me means nothing and I don't comment. The only thing I can tell you is that I expect Stones to play with Jagielka and we know their qualities and we are going to try to be successful," he said.

"Every game is important and we are in the title race. Yes, we are. We need points but every game is difficult.

"Everton is not different. Every team is getting better. Every team has economic power and players to play for title contenders. Every point is more difficult to get."

Chelsea ended up signing Papy Djilobodji from Nantes as a cut-price alternative to Stones.

Mourinho admitted it was not his choice, but that he fully trusted the judgement of those who identified the 26-year-old, who he stressed will be a "fantastic squad player".

"It was the choice of someone I trust completely. Which is the same. I don't know every player. My job doesn't allow me to travel and spend hours watching players," he said.

"In my case, I trust because the same person who told me Djilobodji can be a good squad player was the same person who told me (Kurt) Zouma can be a fantastic player for us."