Is Marouane Fellaini becoming one of Manchester United's and Jose Mourinho's most important players?

How important is Marouane Fellaini to Manchester United? “A lot more important than you can imagine,” was the withering answer of Jose Mourinho, who appeared genuinely frustrated and aggrieved on Monday afternoon when he did not know if Fellaini would be available to him for Tuesday’s return to Champions League against Basel. “I feel weaker without Fellaini in my squad, doesn't matter if it's on the pitch or on the bench,” he added. “I need him.”

In his four years at Old Trafford, the Belgian has been jeered, booed, mocked but rarely, if ever, ‘needed’. The most often-parroted line about him among his detractors within United’s support was that he was ‘not a Manchester United player’. He was regularly said to be a ‘symbol of the post-Ferguson era’. These were not original criticisms but in those early days, even Fellaini would admit, they were often fair.

Certainly, his penchant for elbowing opponents in the face did not go down as well with supporters as you might think, despite the strange tendency for Liverpool and Manchester City players to be on the receiving end. His relatively poor technical ability also did him no favours. Upon David Moyes' arrival, at a time when United desperately needed to address years of neglect in the centre of their midfield, he was their sole signing in the position and not exactly in the mould of Paul Scholes.

It is, on the whole, quite remarkable that Fellaini lasted long enough to see Mourinho walk through the door at Old Trafford. Yet since the Portuguese was appointed, Fellaini has had no reason to look back. He remains on the fringe of the first-team and some way off becoming an established regular, but Mourinho appears to admire him - partly for his particular skillset, but mostly for the quiet and dignified way he responded to the jeers. “He is a player and a person I like and the person is more important,” Mourinho said at the time. “He will always have my trust and protection.”

This trust between player and manager has been reflected in Fellaini’s own performances which have, every now and again, proved pivotal. His display in the Europa League semi-final second leg against Celta Vigo in May was a match-winning one and his attacking contributions late on in games continue to provide United with an extra, unpredictable element. When those behind the excellent United We Stand fanzine suggested the cover of last season’s end-of-term issue be Fellaini’s head emerging out of the Europa League vase, the joke contained a kernel of truth.

On Tuesday night, just as United’s last Old Trafford European campaign ended with a pivotal Fellaini goal, so the new one began with another. The Belgian’s faultless header towards the end of the first half turning United’s dominance over Basel into a tangible advantage and ensured that the remainder of the evening would be something of a procession.

After the comfortable 3-0 victory, it was put to Mourinho that Fellaini’s display may have been his best-ever in a United shirt. For his manager, however, Fellaini’s good performances are too numerous to be distinct. It is far easier, in Mourinho’s book, to pick out a poor one.

“To remember a Fellaini bad performance, I have to go back to last season in the beginning and it was not even a bad performance. Just a naive mistake when he made a penalty in the last minute at Goodison Park,” he said, referencing Fellaini’s cameo against his former club Everton last December, which saw Leighton Baines convert from the spot in the 89th minute to earn a point.

“Apart from that his contributions are always positive,” Mourinho hastened to add. “When he starts, when he's on the bench, he's a very important player for me.” And with Paul Pogba potentially sidelined for some time with a hamstring problem, Fellaini’s importance could yet grow further. It has been a remarkable rise to prominence for one of Mourinho’s favourite players.