Manchester United will be worrying over Marouane Fellaini after the midfielder limped off for Belgium against Bosnia.
The 29-year-old has been in inspired form for the Red Devils this season, as Mourinho's sides injury woes continue.
Fellaini had to be substituted in the 29th minute at the Grbavica Stadium in a Group H World Cup qualifier, according to the Sun.
Fellaini's injury will come as a huge blow for the Portuguese as the huge clash with rivals Liverpool edges closer.
United already have a mini-crisis in their midfield with Paul Pogba and Michael Carrickboth on the sidelines, leaving Ander Herrera to step up.
In eight matches in all competitions this campaign, Fellaini has netted on four occasions.
