Chelsea goalkeeper Edouard Mendy has undergone surgery on a fractured finger sustained in training this week.
The 30-year-old has not played for Chelsea since before the World Cup due to injuring his shoulder during Senegal's run to the last 16 in Qatar.
Mendy was still not fit enough to take a place among the substitutes for Thursday's 1-0 loss to Manchester City in the Premier League.
Speaking ahead of that game, head coach Graham Potter said he expected Mendy – who has played 11 times this season – to return to full fitness within the next week.
However, the former Rennes goalkeeper is now facing more time on the sidelines because of an injury suffered on the training ground.
Edouard Mendy has undergone an operation on a fractured finger sustained in training this week.— Chelsea FC (@ChelseaFC) January 7, 2023
Come back stronger, Edou! pic.twitter.com/cyRNdVl1vc
A statement on Chelsea's official website on Saturday read: "Goalkeeper Edouard Mendy has undergone an operation on a fractured finger sustained in training this week.
"The 30-year-old will work closely with the club’s medical department during his rehabilitation phase."
No timeframe has been given for Mendy's possible return to action.
Spain international Kepa Arrizabalaga has deputised for Chelsea in their past three matches, during which time the Blues have kept one clean sheet and conceded two goals.
Potter's side are 10th in the Premier League and face City again in an FA Cup third-round tie on Sunday.