Marouane Fellaini's United career looks to be in doubt with his contract up at the end of the season.
The Belgian has yet to agree a new deal and the club could be prepared to let him leave for nothing in the summer, rather than sell him in the upcoming transfer window.
Fellaini rejected United's latest offer last month with both player and club yet to reach an agreement over his future.
Fellaini became David Moyes only marquee summer signing in the summer of 2013, when he joined from former club Everton for £27m.
In part because of the stigma of being a Moyes buy, and in part because of his often clumsy and unconventional style, Fellaini's fortunes have fluctuated wildly at Old Trafford.
Fans always need a scapegoat, and for a long time with us, it was Fellaini.
He quickly became the epitome of that turbulent and traumatic campaign under the Scot, but has since found his niche in the side under Louis van Gaal and Jose Mourinho.
An often divisive, and even derided, player, he was booed by a section of the Old Trafford crown when he came on against Spurs last December, having given away a late penalty in the previous match.
But the big man has proved a lot of people wrong - he's felt a strong bond with Jose from the start and is respected and trusted by his manager.
As a result, his confidence and form has risen and he's enjoyed the best form of his career at United over the last year, turning into a key big match player.
He scored in two cup semi-finals last season, against Hull in the EFL Cup and Celta Vigo in the Europa League, and went on to star in the final of the latter as United beat Ajax 2-0 in Stockholm.
The lack of clarity surrounding his contract comes as a surprise, with Mourinho full of praise for his much-maligned midfielder.
The two men enjoy a good relationship, and Jose's influence looks to be a key factor in the decision over whether he stays or leaves.
The Belgian has continued that goalscoring form from last term into this campaign, with four goals in nine games - including a first ever brace for us, against Crystal Palace.
Having worked hard to resurrect a United career that was only heading one way, Fellaini has developed into one of this side's most important players.
He's been injured for some of this season, but made his return against Chelsea last time out after three weeks out with a knee injury.
Fellaini was strongly linked with a move to Turkish club Galatasaray in the summer, which led Jose to joke that the Istanbul side had more chance of signing HIM than the player.
Some United fans would no doubt be happy to see Fellaini leave, but with negotiations ongoing, his future remains unclear.