Jose Mourinho complained about a lot of things last season, but the mentality of some of his players appeared to really get under his skin and he regularly called them out over it in public. A summer cull of the United squad seems inevitable.
The club can't afford to finish sixth again and a return to the Champions League will test the strength of Mourinho's squad.
New players will arrive, but here are six players United should get rid of, and one player they should keep.
Wayne Rooney
This isn't exactly a controversial call, but it still needs to happen. In fact, it needed to happen
a couple of years ago. Rooney arguably should have been sold when Chelsea bid for him back in 2013 as signs of decline were already noticeable.
If Sir Alex Ferguson had remained as manager, the forward would have left, given the pair's relationship appeared fractured.
However, David Moyes succeeded him and felt he couldn't lose the club's most high profile player.
Rooney was given a massive new contract, and has since declined to the point that there's no longer merit in pointing out that he isn't the same player he was.
His touch has deserted him, he looks sluggish and appears to have no chance of ever regaining his place in Mourinho's team.
In fairness, Rooney seems resigned to his fate, and is preparing for the next stage of his career. Everton and China are reportedly options, and it's clear he won't be at Old Trafford next season. The sooner Rooney leaves, the sooner people can focus on how great he once was before the dramatic decline.
Chris Smalling
A year ago, it would have been foolish to suggest United should sell Chris Smalling. The England defender had developed a lot under Louis van Gaal, and was first-choice at the heart of defence, regularly wearing the captain's armband.
However, all of Smalling's progress under Van Gaal seems to have been lost under Mourinho. The 27-year-old made just 13 starts in the Premier League in the 2016/17 season, and seems to have got on the wrong side of Mourinho.
The United manager is said to be unhappy with Smalling's apparent unwillingness to play through the pain barrier. Smalling started the Europa League final win over Ajax, but Eric Bailly, Daley Blind and Marcos Rojo, when he returns from injury, are ahead of him in Mourinho's pecking order.
The United manager will also look to strengthen in defence this summer, which could further reduce Smalling's chances of regular playing time.
Phil Jones
Jones is behind Smalling in Mourinho's pecking order.
Back in 2013, Ferguson said the defender could end up as United's "best ever player." Now, Jones is a meme and probably wouldn't get on the bench if Rojo was fit.
He's still only 25, and could be a useful squad player, but it might be better for both parties if the defender leaves in the summer. Like Smalling, injuries have hampered Jones' progress, and he made just 18 league appearances last season.
Ashley Young
Another uncontroversial choice, Young could be gone by the time you read this. A return to Watford, his first club, would be a perfect fit.
Matteo Darmian
Darmian did well in the Europa League final. However, he wasn't really tested, and didn't cross the half-way line. Darmian is a useful squad player, and capable of playing in both full-back slots.
But is the Italian Champions League quality? Could you see him as part of a team challenging for the league title? In 37 games last season, he arguably didn't convince enough for Mourinho to keep him around.
Adnan Januzaj
Yes, he is still technically a United player, and yes, he should leave the club this summer. Januzaj's career so far has mirrored that of David Moyes' recent struggles.
Given a chance at a big club, after showing potential, he briefly impressed before his form fell off a cliff. He then tried to rebuild his career abroad, failed and ended up getting relegated with Sunderland.
Januzaj is still only 22, and is evidently talented, but it looks like a less physically demanding league would suit him better after his struggles with United and Sunderland in the Premier League.
And one player they shouldn't let go.
Michael Carrick
Carrick will play his United testimonial in June, he'll be 36 in July and has been at the club for 11 years, winning every trophy available. However, the club would be wise to sign him up for another year.
With Zlatan Ibrahimovic and Rooney unlikely to be at the club next season, and David de Gea's future in doubt, United could lose a lot of experience in the summer. For that reason alone, it's arguably worth retaining Carrick.
However, the midfielder can still contribute on the pitch. He played 38 games across all competitions last season, and the side looked more balanced when he was present.
United still need to sign a long-term replacement for Carrick, but he can still play at least 20 games next season, and remains a positive influence for the team.
Alexis Sanchez (Picture: Getty)
Sergio Aguero (Picture: Getty)
