Will United rid themselves of the high earning deadwood that litters the squad? Will Paul Pogba force a move to Real Madrid? Might David de Gea's contract stand-off result in a sale?
And, if there are lots of exits, who will it be that replaces them?
There have been no shortage of United transfer rumours in recent weeks and months, from established names like Toby Alderweireld and Kalidou Koulibaly and others, to emerging talents like Jadon Sancho, Aaron Wan-Bissaka and Tanguy Ndombele.
United tried and failed to implement a Real Madrid-style 'Galacticos' transfer policy in the years immediately after Sir Alex Ferguson retired, but if the recruitment focus is now geared more towards developing players, what of those emerging players already on the club's books?
Unlike most of those at Old Trafford, Axel Tuanzebe and Dean Henderson are United players whose reputations have grown substantially this season after successful loan spells in the Championship with Aston Villa and Sheffield United respectively.
Tuanzebe was a name on many lips when he was named Jimmy Murphy Young Player of the Year in 2015, at which time it also became publicised that the young centre-back had been the first first-year scholar to captain United's Under-18 team since a certain Gary Neville.
The DR Congo-born starlet, who moved to England as a young child and was first picked up by United aged eight, was handed a first team debut by Jose Mourinho in January 2017 and was again on the fringes of breaking through early the following season.
A loan to Aston Villa in January 2018 was intended to help Tuanzebe take the next steps, only for injury to limit his appearances. Another chance came last summer, this time with the promise of a full season at first team level in the Championship, and he took it.
Having started the season at right-back, Tuanzebe began starting regularly in the centre of defence in October when current Villa boss Dean Smith took over. The United youngster remained in the team until suffering a broken foot in December. That kept him out for three months and caused him to miss the start of the club's 10-game winning run. But he has since returned to the starting XI and most recently played in the fraught 1-1 draw with Leeds.
Still only 21 years of age, he has his whole career ahead of him. This season could yet end in helping Villa secure promotion via the Championship playoffs, and would a home grown player on an upward trajectory not be a much better proposition for United looking forward than the often reckless but rarely fit Marcos Rojo or the equally unnerving Phil Jones?
With perfect timing, the Daily Mail has now reported that Tuanzebe will indeed get his chance at United, with an opportunity to impress manager Ole Gunnar Solskjaer during pre-season. The onus is now on the player to keep himself topped up and hit the ground running in July.
Dean Henderson is a United player who has had an even better season on loan than Tuanzebe. The goalkeeper's campaign hasn't been disrupted by injury and his team have gone one better by securing automatic promotion to the Premier League, with Henderson key in that success.
The 22-year-old, who has impressively worked his way up the ladder after previous loans at Stockport County, Grimsby and Shrewsbury, has played all 45 of Sheffield United's Championship games so far this season, keeping a league-high 21 clean sheets.
It won't be as easy for Henderson as it could be for Tuanzebe to get a chance back in Manchester. By the nature of his position it is much more challenging, but added to that is the fact that David de Gea stands in the way of him and a first team opportunity.
It is, however, by no means a closed book. De Gea has come under fire for his performances and is yet to sign a new contract beyond 2020. United find themselves in a very difficult position, but should it come to the Spaniard leaving before next season, why shouldn't Henderson, who impressed every time he has made the jump to a higher level, be allowed to prove himself?
If De Gea were to leave - Juventus, PSG and Real Madrid are those who could pounce - United's rumoured options would be to trigger a €120m buyout clause for Atletico Madrid's Jan Oblak, pay over the odds for Jordan Pickford, a goalkeeper many view as vastly overrated as it is, or take a chance on one of their own, costing nothing and freeing up funds for other positions.
Right now, Henderson appears inclined to stay at Sheffield United for a second loan, perhaps because he knows a first team chance at Old Trafford is not happening if De Gea is still around.
‘I want to play Premier League football at Bramall Lane’#mufc loan goalkeeper Dean Henderson on wanting to stay with #sufc after the Blades promotion to the top flight is confirmed.— Football Heaven (@footballheaven) April 28, 2019
Full interview here: https://t.co/rmat5Kai0M pic.twitter.com/GNyQH5JCPA
The Manchester Evening News reported in late April that United are at least keen to offer Henderson an extension to his current contract. That same story notes that the club is prepared to keep De Gea this summer, even if that means there is a risk of losing him for free in 2020.
It might be that 2020, if De Gea is to walk, is the year of transition to Henderson instead, by then with a full season of Premier League football with Sheffield United under his belt, .
All eyes will remain largely on incoming and outgoing transfers this summer, but United should not and cannot ignore two existing starlets now primed for first team action.