Chelsea captain Reece James will be out of action for several weeks after undergoing successful knee surgery, manager Xabi Alonso said on Friday.
The England international, 26, missed last week's 5-1 win over Bournemouth after suffering an injury in training.
The club said in a statement that "assessments confirmed surgery would be the required course of action", adding the defender had "begun his road to recovery".
"We are all disappointed, and especially for him," Alonso told reporters on the eve of Chelsea's match at Everton.
"He wanted to have a good start after the international break, but in the last training session he picked up an injury. We wanted to be cautious and wait for the result of the tests.
"Now, the surgery has been successful and we will keep supporting him. He will be close to the team as he is a great influence even when he is not available. We wish him a great recovery and while we don't set timelines, he will be out for several weeks."
James has suffered multiple injuries over the past few seasons, which have forced him to miss significant periods.
Last season he enjoyed his best run of games for several years, culminating in his selection for England's 2026 World Cup squad.
The right-back was among one of the five players to withdraw from England duty during the most recent international break and he now looks set to miss the next international window in November.
Chelsea are sixth in the Premier League after six matches of the season.
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