Manchester United defender Aaron Wan-Bissaka is set to be out for some time after sustaining an injury during their 3-1 loss at home to Brighton & Hove Albion at the weekend, the Premier League club said on Monday.
The issue is still being assessed but the right back has been ruled out for "several weeks", United added.
According to a report in The Athletic, the England international, who came on in the 85th minute on Saturday, will be out of action for two months due to a hamstring injury.
Wan-Bissaka's problem adds to a growing list of injuries at United, with midfielder Mason Mount and defenders Luke Shaw and Raphael Varane also sidelined in recent weeks.
United travel to Bayern Munich in their opening Champions League Group A game on Wednesday, before visiting Burnley in a Premier League clash on Saturday.