Despite previously being a divisive figure among United’s support, Fellaini has attained cult hero status at Old Trafford in recent months following a number of match-winning performances.
It is all a far cry from last December when the Belgian was jeered as he came on as a substitute in a 1-0 win over Tottenham Hotspur.
Mourinho is delighted with Fellaini’s turnaround and believes it is a testament to the player’s attitude and personality.
“I think only a strong character could resist the difficulties here,” the United manager said.
“He had some difficult times when people didn’t recognise his qualities, when other managers didn’t like so much the qualities he has.
“He had to be a strong character. He is a fighter, a guy with lots of pride and I am really pleased I helped him reach this level and change the perception the fans have now. I’m really happy for him.”
Fellaini joined United in the summer of 2014 as the first player of the post-Sir Alex Ferguson era, with David Moyes signing him from his former club Everton.
Since then he has been deployed in several positions but under Mourinho, the 29-year-old seems increasingly settled as part of a midfield two.
“I think Marouane has important qualities and I try to use them depending on the situation and what they team needs,” Mourinho said.
“He plays with me as a defensive midfielder, as a second striker, as one of two midfielders. He is a great player. A great character.”
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