The Frenchman was taken off just 38 minutes into Manchester United’s defeat at Watford earlier today.

Martial suffered a nasty clash of heads with Daryl Janmaat earlier in the game, but also appeared to hurt his ankle or knee.

And Mourinho admits he’s not sure what’s wrong with United’s star man.

“I had to be on the game at that time and not worrying with Anthony,” Mourinho said.

“I have not had time to see about the situation. It wasn't an action to go to hospital. It was an action for a free-kick against Watford and obviously not a goal.

“I don't know, I promise I don't know. You are asking about things I cannot tell you.

“I didn't know why he came off, whether he was injured in his knee, his ankle or his head. I don't know.

“I just know, in that moment, he is not in a condition to carry on. I don't know why. I just know I had to change. I don't know yet what happened.”

Watford opened the scoring at Vicarage Road when Martial was dispossed 25 yards from goal by Miguel Britos and the ball eventually found its way to Etienne Capoue who rifled a shot past David de Gea.

PUZZLE: Mourinho isn't sure what happened to Martial

Mourinho thinks the goal should have been chalked off, claiming Britos fouled Martial - rather than winning the ball clearly.

"That’s an obvious situation," he said. I think there is no debate, no controversy. I think that is an obvious situation, like it was obvious last week against Man City but it’s something I don’t control and I cannot even be critical of.

"In the eyes of everyone, it doesn't matter whether you're a Manchester United fan or a Watford fan or whatever, it was obvious."