The 16-year-old forward has turned down a professional deal at City meaning he can move onto a new club, though compensation will have to be agreed due to his age.
If a deal is not agreed between City and United then the two clubs will have to go to a tribunal in order to decide his worth, with the player likely to then sign professional terms with United in September when he turns 17.
The Daily Mail reports that he will cost at least a million pounds due to his potential, though one reason that he may have left is that he cannot get regular time in Manchester City’s under-18 side, and his current team are happy to raise funds by selling him on to United.
McNeill has previously played for United’s youth team, and moved to City’s setup in 2014, and he has scored 600 goals so far at various youth levels.
The newspaper reports that United might not have it all their own way, despite McNeill being a boyhood fan of the club. Wolverhampton Wanderers and Leeds United could be interested in signing the player.
Announcing his departure, McNeill wrote in June: “A massive thank you to Man City for everything over the past six year.
“It’s been such a pleasure to play with some amazing players and I’ve made some amazing friends too.
“Thanks to all the staff and players for helping me develop as a player and also as a person. I wish everyone the very best.”
United have lost Angel Gomes from their youth side after the reserve elected not to sign a new deal at the club, and is expected to sign for Chelsea though the London club will not have to pay a fee for him.