Ole Gunnar Solskjaer is keen to bring the right-back to Old Trafford after his superb season at Selhurst Park.
Palace are not prepared to sell their academpy product on the cheap, however, with the club hierarchy valuing Wan-Bissaka at £70m.
United may not have to pay that much for the defender, but Palace will not accepting anything less than £50m.
The England Under-21 international is thought to be interested in a move, although he has not submitted a transfer request.
And given that Wan-Bissaka is under contract until 2022, Palace do not feel any pressure to sell one of their star players.