Ralf Rangnick has told Anthony Martial to inform him in person if he wants to leave Manchester United, rather than go through his agent.
France international Martial's representative, Philippe Lamboley, said on Friday that the 26-year-old is looking to join a new club in January due to a lack of playing time.
Martial has played just 358 minutes of football for the Red Devils in all competitions this season – the 20th most in the squad – starting only four times.
"Anthony wishes to leave the club in January," Lamboley said to Sky Sports. "He just needs to play. He doesn't want to stay in January and I will speak to the club soon."
But news of the former Monaco player wanting to leave United came as a surprise to recently-appointed interim manager Rangnick.
"I don't communicate with agents via the media and press," Rangnick said. "The player hasn't spoken with me or us about it.
"To be honest, what his agent says via the media is not of that much interest to me. It should be the player.
"If he really has the wish to go to another club it should be the player who informs either the board or myself. I have never spoken about a player via the media and via agents."
Martial's most recent start came in United's 2-0 Champions League win over Villarreal on November 23 under previous interim boss Michael Carrick.
He has not been part of the squad for Rangnick's first three games in charge, which the German coach explained was down to Martial ruling himself out of contention due to injury.
"After the final training session before the Crystal Palace game, after training with the team, he informed the doctor and the medical department that he would not be available because the pain in his knee is too big," Rangnick said.
"We have to wait and see. Maybe he can train again [before playing Brentford on Tuesday] but I have to speak to the doctor first."
United have won both of their Premier League games since Rangnick took charge, the Red Devils edging past Crystal Palace and Norwich City by the same 1-0 scoreline.
The Red Devils have been hit by a coronavirus outbreak and revealed on Monday they are in discussions with the Premier League over whether the clash against the Bees will go ahead.