Erik ten Hag's side are expected to be active during the summer market, with a new midfielder and centre-forward viewed as priorities for the club, who will be back in the Champions League next season.
However, as it stands, it is thought that Man United's budget is around £120m, which would make it difficult for them to sign their leading targets, particularly as a new goalkeeper would also be required if David de Gea does not sign a new contract at Old Trafford.
According to the Daily Mail, the Red Devils are prepared to listen to offers for as many as 13 players, with Harry Maguire, Anthony Martial and Jadon Sancho among those who could depart.
The report claims that Maguire, who struggled for action during the 2022-23 campaign, is likely to be available for a fee in the region of £40m.
Sancho could also allegedly leave, with Man United looking for around £40m for the England international, who has largely struggled to show his best form since arriving from Borussia Dortmund two years ago.
Martial, meanwhile, is said to be valued by the 20-time English champions at £25m, with the Frenchman also potentially departing despite the team's lack of options in the final third of the field.
Donny van de Beek, Fred and Anthony Elanga are all said to be available for £20m each, while Hannibal Mejbri, Alex Telles, Eric Bailly and Brandon Williams are also up for sale this summer.
Zidane Iqbal's future has now been decided, meanwhile, with Man United confirming that the midfielder has left the club to make the move to FC Utrecht.
Scott McTominay's future has also been called into question in recent months, with the Scotland international no longer considered to be a regular starter for the club.
Newcastle United were linked with the midfielder in January and are thought to be preparing to reignite their interest this summer, with £40m likely to be enough to convince Man United to sell.
Dean Henderson, meanwhile, is believed to be available for £20m, with Nottingham Forest said to be keen to sign the goalkeeper on a permanent basis this summer.
De Gea is yet to sign a new deal at Old Trafford, but Ten Hag allegedly does not have Henderson in his plans even if the club's current number one goalkeeper leaves on a free transfer this summer.
Man United are yet to make a signing during the current window, but they remain keen on Chelsea's Mason Mount despite thus far being unable to agree a transfer fee with the Blues.