Manchester United are not sure about a return timetable for Scott McTominay.
The central midfielder went down late against Brighton and Hove Albion in the Premier League on Sunday.
McTominay has withdrawn from the Scotland squad, but it is unclear if he will be ready to play after the international break.
Sky Sports says there is no definitive date for McTominay's return.
The Scottish international has been nearly ever present for United this season.
Manchester United face Sheffield United in the Premier League on November 24.
