Manchester United fans watched in pain as Raphael Varane limped off in France's Nations Leaguefinal win over Spain.
Les Bleus won the game after Karim Benzema and Kylian Mbappe fired in the second-half after Spain went ahead 1-0.
Varane was replaced with Dayot Upamecano just before half-time after medical staff assessed him on the pitch.
There has yet to be an update from Didier Deschamps about the injury.
It is bad news for Ole Gunnar Solskjaer, who has been dealing with captain Harry Maguire sidelined with injury.