Sancho, 25, is one of the four man United players who missed the US pre-season tour after he should have found a new club this summer.
Various reports have suggested that the winger is about to become a member of Juventus, but after the signing of Francisco Concukicao, which could now be in danger.
According to Gianluca di Marzio, the club has now suspended conversations about a move for Sancho and will have to sell at least one winger to make a deal happen.
Nico Gonzalez and Timothy Weah will both leave this summer, with the last one in conversation about a move to Marseille.