In two years at United Ander Herrera has promised so much but delivered little and his future, like many of team mates, is uncertain.
Herrera was the star of Athletic Bilbao's 2011-12 season, a campaign in which they reached the Europa League final (dispatching of United en route) and the Copa del Rey final.
It was thought to be those performances against us in that European tie that persuaded United to sign the Basque when he arrived for £24 million in the June.
When he signed, he appeared to be exactly the type of player we needed: an all-action midfielder to link the play and bring energy and industry to an engine room in desperate need of surgery.
Eight goals last term was not a bad return for an attacking mid, and there were flashes of brilliance- the debut goal, exquisite strike at Leicester and his brace against Villa that was reminiscent of Paul Scholes.
But yet, since then, he has struggled for consistency and has yet to nail down a starting place under Louis van Gaal.
Watching Herrera, you're left with a feeling of what might have been: a player who looks as though he can dictate a match and make a difference but never quite manages to do so.
Part of this problem is down to his style of play and role in the side: is Herrera a no.10 playmaker, a box-to-box engine ala Paul Scholes or a deep-lying creator?
It's been difficult for Herrera to establish himself in his favoured position 'in the hole' with Wayne Rooney, Juan Mata, Memphis and Adnan Januzaj all having vied for that position before Van Gaal seemingly settled on Jesse Lingard.
Two seasons in and we're still not sure what he brings to the table: he loves the club with a passion and is a likeable guy but there's no real identity in his play and too many question marks.
I'm still not convinced he's good enough to be our playmaker: he's wasteful in possession and his lightweight frame is not up to the physical and robust style of the English top flight.
In many ways, Herrera's uncertainty mirrors that of many of his team mates.
Are his struggles down to a lack of faith in him by Van Gaal and therefore a lack of game time?
Has he struggled for consistency because he's being played in many unfamiliar positions?
Or is he just not good enough?
Do we keep him at the club and hope Herrera flourishes under a new manager or do we cash in and put him down as another Van Gaal flop.
Whatever happens from here, the jury's still very much out on Ander.