Ben Chilwell requires knee surgery and could miss the rest of the season.
The England international suffered anterior cruciate ligament damage during Chelsea’s 4-0 Champions League win against Juventus on 23 November, but the Blues hoped he would be able to recover without an operation.
Boss Thomas Tuchel said at the time that Chilwell would be assessed after six weeks and would then either be close to a return or would have to have surgery.
The initial signs were positive and, with Chilwell seemingly responding well to treatment, the club were hopeful he would be back sooner rather than later.
However, it has since become apparent that an operation will be needed, potentially ruling him out for several months.