Marouane Fellaini is facing a spell on the sidelines after picking up a knee injury during Manchester United's 4-0 loss to Chelsea on Sunday (23 October). The Belgian midfielder will be absent when the Red Devils take on rivals Manchester City in the fourth round of the EFL Cup on Wednesday (25 October).

The midfielder suffered the injury after a rash challenge by Blues defender David Luiz, which many believe should have seen the defender sent off. Fellaini was forced off at half-time and according to the Mirror, the injury could see him miss several weeks, but the extent of the injury will only be revealed following a scan, which can be performed only after the swelling subsides.

After struggling for game time under Louis van Gaal last season, the Belgium international has been a regular under Mourinho, who has deployed him in his favoured defensive midfield role. He started the first five games of the season, but was left on the bench for the next two before being recalled for clashes against Liverpool and Chelsea.

The midfielder's latest injury, if deemed to be serious, could see him miss a number of important clashes in the Premier League and Europa League including United's game against Arsenal, which will be played at Old Trafford on 19 November. The 4-0 thrashing by Chelsea and the injury to Fellaini, however, were not the end of the Red Devils' misery as the evening got worse when Eric Bailly was forced off with a knee injury, which Mourinho feels could be serious.

Marouane Fellaini
Marouane Fellaini suffered a knee injury following a rash tackle by Chelsea defender David Luiz Getty

The Ivory Coast international has been one of United's best players this campaign, and has clearly justified his £30m ($36.6m) price-tag. He had formed a strong partnership at the heart of United's defence first with Daley Blind and in recent weeks with Chris Smalling. Bailly's absence will be a big blow, with important clashes coming up in the league and Europe.