The United hierarchy believe that fringe players need to be offloaded before Mourinho invests on new ones in order to control costs.
The United manager has currently spent £285m on 6 new players during his two-year reign with the Red Devils.
The Old Trafford bosses believe the 13.5% increase in their wage bill (released in September 2017) is too high and now stands at £263.5m.
Most likely to departure the club this January are outcasts; Luke Shaw, Matteo Darmian, Juan Mata and Maroune Fellaini, whose United contract runs out in the summer of 2019.
The Portuguese boss has already attempted to cut United’s wage bill with the sales of sixteen squad players since his arrival in May 2016. French Midfielder, Morgan Schneiderlin and Dutch Forward, Memphis Depay, were big sales while the departures of Bastian Schweinsteiger and former club captain, Wayne Rooney, helped to decrease the enormous wage budget at the Manchester Club.