Kurt Zouma is set to miss up to six months of football after damaging his anterior cruciate ligament.
The Chelsea defender landed awkwardly during Sunday's 1-1 draw with Manchester United and required a stretcher to leave the Stamford Bridge pitch.
Zouma, 21, will now have surgery in the next day or two and will then spend around half a year doing rehab and recovery before eyeing a return in mid-to-late August.
The injury gives Zouma no chance of forcing his way into the France squad for Euro2016 this summer.
A statement on Chelsea's official website 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, who has made 31 appearances in all competitions this season, was confident he would be back bigger and better following his injury layoff.
Scan today has shown I injured my ACL. I will have surgery this week & will come back stronger. Thank you everyone for all the messages
— Kurt Zouma (@KurtZouma) February 8, 2016
