Manchester United forward Alejandro Garnacho left Old Trafford on crutches following his side's 0-0 draw with Southampton.
The 18-year-old has been a revelation for Erik ten Hag's side this season having been promoted from the club's academy.
But he could face a spell on the sideline after being taken off in injury-time despite entering the field in the 73rd minute against the Saints.
Garnacho was seen wearing a grey protective boot and using the aid of two crutches as he exited the stadium after his right ankle was caught by Kyle Walker-Peters’ challenge.
Nevertheless, Ten Hag has downplayed the youngster's injury, insisting the team needed more players in attack after seeing Garnacho limp.
‘He was limping a little bit after a bad tackle so in the end I thought I would bring on another striker as we were already downsized to 10 men. I don’t think it’s (the injury) is too bad,' the United boss said.
If Garnacho is to face a lengthy spell on the sideline, it would come as a blow to United, who have Europa League and FA Cup fixtures to come in the coming week.
Ten Hag's side were already without the likes of Donny van de Beek, Christian Eriksen, Marcel Sabitzer and Anthony Martial on Sunday.
Midfielder Casemiro is also set to miss the club's next four domestic matches after receiving his second red of the season against Southampton.
United will return to action on Thursday against Real Betis in the Europa League before making a trip to Fulham next weekend.