Lucas Hernandez will miss the rest of the World Cup, and likely the remainder of the season, after suffering an anterior cruciate ligament injury.
France were dealt a huge blow by injuries ahead of their campaign in Qatar, which began with a 4-1 rout of Australia on Tuesday.
Paul Pogba, N'Golo Kante, Karim Benzema and Christopher Nkunku were all ruled out before the tournament started, and now Didier Deschamps has lost another key player.
Hernandez suffered the injury nine minutes into the win over Australia, as he went down clutching his right knee after being turned by Matthew Leckie in the build-up to Craig Goodwin's opening goal.
Deschamps and Hugo Lloris both conceded after the match that it did not look positive for the Bayern Munich defender, and France have now confirmed the 26-year-old's ruptured his ACL.
Given the extent of his injury, Hernandez will miss a chunk of the rest of the 2022-23 campaign when it resumes after the World Cup.
"Like the whole group, players and staff, I am extremely sorry for Lucas," said Deschamps.
"We are losing an important element. Lucas is a warrior and I have no doubt that he will do everything possible to return to the game.
"I know him well. Courage, he will have it, that's for sure. On behalf of the group, I wish him the best possible recovery."