Manchester United defender Raphael Varane was forced out of the UEFA Nations League final before half-time due to injury.
The France centre-back hobbled off after appearing to pull up while running, and was seen with ice on his right thigh after being replaced by Dayot Upamecano on 43 minutes.
It will come as a major concern for United boss Ole Gunnar Solskjaer, who is already without Harry Maguire for their next Premier League game away to Leicester on Saturday.
Varane's team-mates went on to win the final and he posted a picture on his Instagram page of him holding the trophy, but made no mention of his injury - and neither did the France boss Didier Deschamps during his post-match media obligations.
Varane is due back at United's Carrington training base later this week where he is likely to be assessed following the knock, which is his first since joining United from Real Madrid in the summer.
Varane missed the first Premier League game of the season against Leeds because he was not registered in time and was then on the bench against Southampton as he got up to speed with Solskjaer's plans, but has played 90 minutes in every Premier League game since.
Manchester United's gruelling run
Manchester United face a formidable set of fixtures in October and November as they look to keep pace in the Premier League and ensure Champions League qualification, with Liverpool, Chelsea, Arsenal, Tottenham and the Manchester derby looming domestically.
October 16: Leicester (a) - Premier League, kick-off 3pm
October 20: Atalanta (h) - Champions League, kick-off 8pm
October 24: Liverpool (h) - Premier League, kick-off 4.30pm, live on Sky Sports
October 30: Tottenham (a) - Premier League, kick-off 5.30pm, live on Sky Sports
November 2: Atalanta (a) - Champions League, kick-off 8pm
November 6: Man City (h) - Premier League, kick-off 12.30pm, live on Sky Sports
November 20: Watford (a) - Premier League, kick-off 3pm
November 23: Villarreal (a) - Champions League, kick-off 5.45pm
November 28: Chelsea (a) - Premier League, kick-off 4.30pm, live on Sky Sports
November 30: Arsenal (h) - Premier League, kick-off 8pm