The signings of Bastian Schweinsteiger and Morgan Schneiderlin will further strengthen Louis van Gaal's midfield options.
However there is not room for all of them in the starting line-up which begs the question, who is going to lose out?
The Dutchman arrived last summer after a successful World Cup with van Gaal. Perhaps his best trait is his versatility.
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He has proven that he's capable of playing holding midfield and left-back. Blind's place in United's midfield is in serious doubt though.
He looks like the weakest of the options that will be at van Gaal's disposal.
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Lacking the vision of Carrick and the tackling ability of Schneiderlin. He may have performed well in the position last season but that was likely only a temporary measure.
It seems likely that he will be competing with Luke Shaw at left-back.
The Englishman is somewhat of an unsung hero at United because he is so quietly effective. Indeed it's possible to miss his contribution completely, but make no mistake it's there.
The team missed Carrick whenever he wasn't playing last season. His impressive 89.6% pass accuracy makes him the calming influence in midfield.
However he's 33 now and there are serious question marks over his fitness. He struggled with injury last season and only appeared 18 times.
As he gets older, his appearance figures will only drop. Carrick being rotated with Schweinsteiger is a real possibility.
The most successful signing made last summer. There was distinct improvement from Herrera over the course of last season. His six goals last season was a healthy return considering it was his first in England.
He's the most deserving of a place in the middle of United's midfield, dropping him would be an injustice.
With the arrivals of Schweinsteiger and Schneiderlin, Herrera could find himself playing in a more advanced position, shadowing Wayne Rooney.
A transfer that has split opinion. Some believe his experience will be invaluable others think he's old and past it.
It's true that he's not the player he was five years ago. He's 30 now and coming towards the end of his career, so there's reason to be sceptical.
Just how regularly he'll play is unclear. His appearance figures have been declining over the last four years.
The Premier League is widely regarded to be more demanding than the Bundesliga so it's unlikely that his appearance figures will increase. However rotation with Carrick could be beneficial for both players.
Enjoyed a breakthrough season at United, forming an effective partnership with Ashley Young down the left but his long-term future is still in doubt.
The Belgian became an effective target man for United last season. However, he will surely not fit the style of play van Gaal eventually wants to implement.
With United's summer recruitment in full swing, it looks like Fellaini is going to struggle to compete with the star-names at the club.
His red card on the final day of last season will rule him out of the first three games of the new season. This won't help his cause and breaking back in will be difficult if not impossible.
He's undoubtedly got a lot to give to a club, but that club may not be United for much longer.
With United set to pay a fee in excess of £25 million for the player, he will surely be a first team regular.
Schneiderlin boasts important Premier League experience which means fans should perhaps be more excited about this capture than that of Schweinsteiger. At the age of 25, he is only going to get better.
United have been in desperate need of a player in the mould of Nemanja Matic and in Schneiderlin they might have finally found their man. He will bring defensive qualities similar to those of Matic but will bring more quality in attack than the Chelsea man can provide.
Mata was criticised for his performances under Moyes but last season, he really proved himself at Old Trafford.
The Spaniard silenced those who said he didn't perform in the big games by striking twice against Liverpool before netting against City.
Despite a good season there are still some apparent weaknesses in his game. He lacks pace and he's not strong enough.
These are minor flaws in his game though. After the last campagin he has earned his place in the side for next season.
Unfortunately for him playing in his favoured number ten position may not be possible. Instead he could find himself pushed out on to the wing again.
It's a position that he became frustrated with at Chelsea, will the same happen again?
Sadly, it looks like Young could be one of those to lose out. It will be shame because he really was excellent last season.
Many regarded him as the sides most consistent outfield player. He is one of those that has earned his place in the side but Depay's arrival has cast doubt on his first team spot.
He is 30 now and can't be seen as a long-term option. If players are being picked on performance levels, then the truth is that Young should be one of the first names on the team-sheet.
ANGEL DI MARIA
Absolutely flopped in his debut season, despite a promising start. There has been much speculation over his future. Bayern and PSG are reported to be suitors.
However it seems that United want to hold on to their record signing this summer. They'll hope that the risk pays off.
If he stays then he will surely be a regular next season. They have the chance now to recoup much of his transfer fee and keeping him would indicate that he's very much part of van Gaal's plans.
We'd likely see the very best of him playing from the wings. It will be a make or break season for him at Old Trafford.
A really exciting prospect for United. The club has invested a lot in the 21-year-old and will be hoping he'll justify his price tag.
Don't get carried away though. He boasts an impressive record in the Dutch league but it's by no means a foregone conclusion that he'll tear things up in the Premier League.
He'll find England more physically demanding and may need time to adapt. However, he has a manager who he knows which will be helpful.
After paying nearly £30 million for the Dutchman he will surely be one of the first names on the team sheet next season. A position on the left-wing is likely with Rooney leading the line.