Diallo was the star man and limped off late in the second half to a standing ovation, being replaced by Mason Mount.

“He had to come off unfortunately,” Van Nistelrooy said. “He’s being assessed now.

“Of course I hope that he will be available for Sunday, but we have to wait and see.”

The victory moved United up to 15th as the 36-team league phase reached the halfway point, with their next Europa League match against Bodo/Glimt being Amorim’s first match at Old Trafford.

The 39-year-old’s first fixture will be just before that at Ipswich after an international break the Red Devils head into following Sunday’s home match against Leicester.

United beat the Foxes 5-2 in the Carabao Cup in Van Nistelrooy’s first game in temporary charge, with the fan favourite determined to end his stint on a high.

“For me, it’s important now to carry on and build on the results of Leicester, of Chelsea and of PAOK,” he said.

“I think the second half we can build on, result we can build on.

“First European home win after one year. We addressed that in the dressing room, and it was time to change that.

“The players did very well doing so, and Sunday is a big game for us in the league to get a good performance in again.”

Amorim takes charge of his final Sporting Lisbon match at former club Braga on Sunday after Van Nistelrooy leads United against Leicester with his role as assistant unclear beyond then.

“I think that Ruben (from) what he’s saying is he focuses on Braga, and I focus on Leicester,” the caretaker boss added.

“I think that’s a great one for now, and that shows that we’re focused on the day by day job and get the maximum out of the team.

“Let him focus on Braga, I’ll focus on Leicester, and we’ll see after that.”