The twin brothers, Tyler and Jack, currently play for fierce rivals Manchester City's youth team.
Now though, the pair look poised to cross over to the red side of the city.
According to football transfer expert Fabrizio Romano, the brothers are expected to join the club for British record fees for Under-16 players.
Theo Walcott's move to Arsenal from Southampton at 16 is the current record for the most costly 16-year-old ever in the UK, with the deal eventually costing the Gunners £9.1million after an initial £5million fee.
The Red Devils are reportedly locked in talks with Man City for the duo, with the deal expected to be announced soon.
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Tyler and Jack both play international football at Under-16 level, with the former representing Scotland like his father did and the latter playing for England.
The youngsters are both central midfielders, just like their dad.
Fletcher - who made 342 appearances for Man United - is still heavily involved at the club, working as their technical director.
Now his sons look set to be the latest signings for the club's academy.
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Meanwhile, United are set to sell Red Devils academy product Robbie Savage's son Charlie to Reading.
The youngster captained the Red Devils in their opening pre-season fixture against Leeds, but is he now expected to sign for the League One outfit on a permanent deal.
Academy graduates Zidane Iqbal and Ethan Laird have also left the club this summer.