Chelsea have announced centre-half Thiago Silva has suffered knee ligament damage and will be out for an unspecified period.
The veteran broke down during defeat at Tottenham on Sunday.
"Having sustained a knee injury during the first half of Sunday's match against Tottenham Hotspur, Thiago underwent further assessment and a scan on his return to the training centre on Monday," a Chelsea statement said.
"Scan results from those assessments have confirmed damage to Thiago's knee ligaments and he will now work closely with the club's medical department during his rehabilitation to return to action as soon as possible."