Manchester United manager Jose Mourinho unsure on severity of Romelu Lukaku's injury

Lukaku was forced off at the start of the second half against Arsenal with a foot injury

Jose Mourinho does not know whether Romelu Lukaku will be fit to play in the FA Cup final after the Manchester United striker came off injured in Sunday’s victory over Arsenal.

Lukaku was replaced by Marcus Rashford at the start of the second half after suffering a foot injury in a challenge with Konstantinos Mavropanos and subsequently limped down the Old Trafford tunnel.

The Belgian has been almost ever-present for United this season, missing just one league outing so far, but his injury will spark fears that he could sit out of next month’s Wembley final against Chelsea.

Mourinho was still unsure on the severity of Lukaku’s problem after the final whistle but he expressed his hope that the injury will not prove to be serious.

“I don’t know,” he said, when asked whether United’s top scorer could be a doubt for the remainder of the season. “To be out is not OK.

“He wants to always play all the time, he is never tired, so when he has small things he doesn’t care, he wants to go.

“To say immediately ‘change’ is because he couldn’t play. But, three more weeks until the final. I just know [the injury] is on his foot.”

United will travel to Wembley to play Chelsea on 19 May, with Mourinho hoping to end a season of improvement at Old Trafford with a trophy.

“I don’t know,” Mourinho added, when asked specifically about Lukaku’s involvement in the FA Cup final. “I don’t think it is something. I hope it is not something that keeps him out of a game in three weeks’ time but I don’t know.”