Manchester United boss Ralf Rangnick has warned Anthony Martial he doesn't appreciate the Frenchman's agent speaking for him.

Martial's agent, Philippe Lamboley, said on Friday Martial wants a transfer in the January transfer window and that he would 'speak to the club soon'.

United manager Rangnick dismissed Lamboley's public comments and advised Martial that he should tell the club if he wants to leave.

"I don't communicate with agents via the media and press," Rangnick said. "The player hasn't spoken with me or us about it.

"After the final training session before the Crystal Palace game, after having trained with team, he informed the doctor and the medical department that he would not be available because the pain in his knee is too big. We have to wait and see.

"Maybe he can train again [on Sunday] but I have to speak to the doctor first. To be honest, what his agent says via the media is not of that much interest to me."

When asked if he would speak to Martial for his version of events, Rangnick replied: "No. Then I would react to what his agent has said and 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."