Manchester United are facing a testing night in the Champions League ahead of their FA Cup quarter-final at home to Albion.

And they could be without Ander Herrera after the midfielder suffered another injury setback .

United ground out a 0-0 draw at Sevilla in the first leg of their last-16 tie last night.

The return at Old Trafford takes place on the Tuesday ahead of the Seagulls’ visit.

A big win at the Sanchez Pizjuan might have given United the chance to rest big players in the days before Albion go north west for an eagerly-awaited quarter-final.

Instead they face a potentially tense evening, especially if they concede an away goal.

United had David De Gea’s exceptional display in goal to thank from a match dominated by Sevilla.

Having missed the last three matches with a muscle issue, Herrera limped off and is now facing another spell on the sidelines as United's medical team comes under scrutiny.

"I think it's a bad injury," Mourinho said.

"He had a small injury that stopped him for the last couple of matches, but the medical department gave him 100% ready for the last Saturday (at Huddersfield in the FA Cup).

"We didn't play him to give more work and more protection, but it looks like he was not fully fit.

"The medical department gave him fully fit. They gave him fully fit Saturday and he trained Saturday, Sunday, Monday, Tuesday, and he looked fit.

"The way he was playing during the time he was on the pitch, I think he showed that intensity that is only possible when you are fit.

"He was pressing really high, we start the match not giving one inch to (Ever) Banega, pressing him really high.

"Ander was one of them, Scott (McTominay) was the other one, and you only do that when you feel really good.

"Then the back-heel creates a contraction in the muscular area where he had a fitness problem, and now we have the proof that he was not 100% fit."