Chelsea have announced that defender Kurt Zouma is expected to be out of action for six months due to an anterior cruciate ligament injury.
The 21-year-old was stretchered off in the 59th minute of his side's 1-1 draw against Manchester United at Stamford Bridge on Sunday after landing awkwardly.
After leaving the stadium on crutches, Zouma told L'Equipe that he was feeling "better", but now he has revealed that he requires an operation.
"Scan today has shown I injured my ACL," Zouma tweeted. "I will have surgery this week & will come back stronger. Thank you everyone for all the messages."
A statement from the club read: "Chelsea Football Club's medical team have diagnosed that Kurt Zouma sustained an injury to his anterior cruciate ligament during yesterday's Premier League game against Manchester United.
"Kurt will undergo surgery in the next 48 hours and is expected to be out for approximately six months."
Zouma has started 21 of Chelsea's 25 Premier League games this season.