Manchester United midfielder Marouane Fellaini has suffered medial ligament damage in his left knee that will rule him out for a "couple of weeks," the Belgium national team has confirmed.
Despite sitting out of training for much of the week, Fellaini was cleared to play in Saturday's (7 October) penultimate 2018 World Cup qualifier against Bosnia and Herzegovina by manager Roberto Martinez. His evening lasted just 29 minutes however after picking up a knock that forced him to be substituted, with Anderlecht's Leander Dendoncker onto replace him.
While Fellaini was able to leave the stadium without the need for crutches, Martinez sparked concern after revealing fears over ligament damage post-match. The Belgian FA have since confirmed the injury which immediately rules him out of Belgium's final qualifier against Cyprus, but more importantly, Manchester United's trip to Liverpool on Saturday 14 October.
United may breathe a slight sigh of a relief given their midfielder escaped without cruciate ligament damage which would have extended his time in the treatment room from weeks to months.
But it will be little consolation for Mourinho, who is already short on numbers in midfield ahead of their biggest game of the season so far.
Ahead of that trip to Anfield, United are yet to set a timeframe for Paul Pogba's return, with his manager classifying his hamstring problem as a "long-term problem."
Michael Carrick has also been unavailable for his side's last two games through injury, with Nemanja Matic, who has played every minute of the Premier League campaign so far, and Ander Herrera Mourinho's only other experienced options.
20-year-old Scott McTominay represents their only other midfield possibility, although Mourinho did turn to centre-half Axel Tuanzebe to fill in higher up the pitch during another injury crisis at the end of last season with the 19-year-old starting as a defensive midfielder in games against Tottenham Hotspur, Southampton and Crystal Palace.
In addition to that titanic clash with Liverpool, Fellaini is also set to miss the Champions League trip to Benfica and the Premier League visit to Huddersfield Town. United will be hopeful of having him available once again for the visit of Tottenham Hotspur on 28 October.
Fellaini teammate's Romelu Lukaku meanwhile missed the thrilling 4-3 win over Bosnia and Herzegovina with Belgium deciding not to select him from the squad after a recent ankle problem. The former Everton striker could return to the first-team for Tuesday's qualifier against Cyprus.