The Belgian midfielder joined the Red Devils as David Moyes’ first signing from Everton back in 2013 but he has been something of a peripheral figure in the set-up at Old Trafford.
Fellaini is well-known for his combative style of play and Mourinho has showed his faith in the Belgium international on a number of occasions since the Portugese coach took charge last summer.
Now, Mourinho has underlined how important he feels Fellaini is to his team at Old Trafford.
Mourinho told a news conference at Carrington on Monday: “He’s a very important player for me – much more important than what you can imagine.
“I feel weaker without Fellaini in my squad. It doesn’t matter if it is on the pitch or if it is on the bench, so if his conditions improved he will be selected because I need him. But in this moment I cannot say yet.”
Manchester United are currently gearing up for their crunch Premier League clash against Everton at Old Trafford on Sunday afternoon as they look to get back to winning ways in the top flight.
The Red Devils were held to a 2-2 draw by Stoke City last weekend as they dropped their first Premier League points of the season.
Mourinho has been tasked with steering Manchester United to Premier League glory for the first time since Sir Alex Ferguson retired at the end of the 2012-13 campaign.
The Portuguese coach led Manchester United to both EFL Cup and Europa League glory last season.
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