Jose Mourinho appeared to pick a fight with the Manchester United medical staff for declaring Ander Herrera fit to play against Sevilla on Wednesday after the Spanish midfielder was forced off with a hamstring injury early on.

Mourinho picked Herrera alongside youngster Scott McTominay at the expense of Paul Pogba in United’s first Champions League knockout game in four years but was forced to call on his record signing to replace the Spaniard, who fell to the floor in pain after attempting a back-heel in Sevilla’s area.

It was Herrera’s first game since the defeat to Tottenham Hotspur at the end of January, with the a hamstring injury keeping him out of action for the next three weeks.

“I think it is a bad injury,” Mourinho said. “He had a small injury that stopped him from playing the last couple of matches, but the medical department said he was 100 per cent ready for last Saturday [against Huddersfield]. We didn’t play him to give him more work and more protection, but it looks like he was not fully fit.”

And he added: “And then the back-heel creates a contraction in the muscular area where he had the previous problem and now we have proof he was not 100 per cent fit.”