The Belgian was heavily criticised last weekend after he conceded a late penalty for Man United’s 1-1 draw with Everton at Goodison Park.
He was introduced in the closing minutes of the game by Mourinho to close out Man United’s 1-0 lead over Tottenham thanks to Henrikh Mkhitaryan’s opener at Old Trafford and was booed by supporters.
Speaking after the game, Mourinho backed Fellaini as a player that he likes and completely trusts.
“I accept it because you have to accept everything from the fans,” he said.
“Especially fans who give so much without getting results he’s a player that I like and a person that I like and the person is more important than the player.
“He has my support and my trust.”
Man United claimed all three points against Spurs as they held on to secure the 1-0 lead, leaving them sixth place in the Premier League table, but they did well to close the gap on the top four.
Hopes are the side can carry the momentum forward as a much-needed win when they face the likes of West Brom, Sunderland and Middlesbrough in the Premier League over the Christmas period.