Manchester United boss Ole Gunnar Solskjaer has insisted that he understands why Donny van de Beek was frustrated at not featuring against Villarreal in the Champions League on Wednesday night.
The Netherlands international was visibly angered when he was not used as a substitute against the Yellow Submarine, and the 24-year-old is believed to be keen to leave Old Trafford in January.
Solskjaer has said that he understands Van de Beek's frustration and has no concerns over the Dutchman's conduct, providing that it does not affect the team.
"You know, I manage a squad full of international footballers, competitive footballers who want to make a difference, who want to play. They all want to be on the pitch, of course they do," the Manchester Evening News quotes Solskjaer as saying at Friday's press conference.
"Donny was ready to come on, as all players should be. I've been a sub more than anyone in this club probably - I must have a record appearance as a sub - and you have to be ready all the time. I've been not very happy a few times but that is the decision the manager makes.
"Alex [Telles] was coming off as a left-back and Fred did that job well. So I understand the frustration, of course, every player is keen to play, that's got to be built into energy and determination for when you get on and show me.
"It's not just Donny, it's players, I've got a squad of internationals and if we're going to be successful we need positive energy, no sulkers. Donny has never affected his teammates negatively. As soon as I see players affecting the team negatively then that's a different scenario and I'll probably be firmer."
Van de Beek has only played 141 minutes of football for Man United at the start of the new season.