United want around £18million for Wan-Bissaka and, should they sell, would then look to hold further negotiations with Bayern Munich for right-back Noussair Mazraoui.
United had a bid for Mazraoui and teammate Matthijs de Ligt rejected last week.
The club also remain keen on PSG midfielder Manuel Ugarte, but it's thought they will need to sell to raise funds to sign the Uruguayan.
Man United are willing to sell Aaron Wan-Bissaka, with West Ham interested in the defender
McTominay’s future at Old Trafford is up in the air once again after United rejected a £30m offer from West Ham last summer.
A year on, it’s understood that United will listen to bids of £25-30m for the Scotland international who has 11 months left on his contract, although United have the option to extend it by another year.
Fulham have made at least one other bid for McTominay who is also attracting interest from Turkish clubs Galatasaray and Fenerbahce. The 27-year-old featured in United’s 3-2 win over Real Betis in San Diego in the early hours of Thursday.
United are looking to offload either McTominay or Casemiro this summer so they can sign a new defensive midfielder.