Jose Mourinho has insisted he will not force any of Manchester United's fringe players to leave Old Trafford in January, but said it "hurts" to leave the likes of Memphis Depay, Ashley Young and Marouane Fellaini out his match-day squads.

The United manager, who has admitted that Bastian Schweinsteiger could remain at the club for the rest of the season after a surprise return to contention, has handed Depay and Young just a handful of appearances this season, with Belgium international Fellaini dropping out of the picture in recent weeks.

Uncertainty also surrounds the futures of Matteo Darmian, Morgan Schneiderlin and Marcos Rojo, with Mourinho to target at least one new signing in the transfer window.

But the Portuguese admits that all of his out-of-favour players are impressing him with their effort and commitment, making it harder for him to tell them they have no future at the club.

"I will not push anyone because nobody deserves that," Mourinho said. "The way they work, they don't deserve that.

"On Wednesday I was in my hotel and my assistants came here to train the group of five who were not selected and stayed here. They told me what I expected -- amazing effort, amazing commitment, amazing professionalism.

"Memphis Depay, Ashley Young, Marouane Fellaini -- the people who stay here were fantastic.

"It hurts me not to select them, so you see that sometimes I do a little bit of rotation. One day I play one, another day I leave one at home, then put one on the bench.

"Nobody deserves to be pushed, for me to say 'it's better for you to leave.'"

Mourinho has conceded, however, that he will not stand in a player's way if he claims that the frustration of being overlooked is too great.

"I have to understand that frustration is something that comes to the players now and again in certain moments of their careers and seasons," he said.

"Frustration is something that arrives and we will analyse it if anyone who shows me that frustration has a desire to leave.

"For me, it's very comfortable to have all of them. But it hurts me."