– Doctors blamed for Herrera injury –
The injury to Herrera came after the Spaniard had been passed fit to return from a hamstring injury that had kept him out of United’s previous three games.
He could now face another untimely spell on the sidelines, with United’s programme including Premier League games against Chelsea and Liverpool before the Sevilla second leg on March 13.
“The medical department gave him fully fit. On the pitch he showed the intensity that is only possible if you are fully fit,” Mourinho said.
“Then it was a back-heel and a back-heel creates a contraction in the muscular area where he had the biggest problem, and now we have proof that he was not 100 percent fit.”
Mourinho said the scoreline “reflected what the game was”, despite the Old Trafford side managing just one shot on target all evening.
Sevilla created almost all of the chances, but could not find a way past an inspired David de Gea, who made two stunning saves from Steven N’Zonzi and Luis Muriel late in the first half.
“Even with a couple of mistakes the team defended well,” Mourinho said. “When we made the mistakes David was obviously there and that is the reason why he is what he is.”
United are hoping to reach the quarter-finals for the first time since 2014, while Sevilla have never made it past the last 16 of the Champions League in three attempts in the last decade.
Their coach Vincenzo Montella believes his side have a good chance of progressing, despite struggling recently in big matches away from home.
“I think this Sevilla have to always play to score and try to be superior to our opponents,” said the Italian.
“It is not always possible but that is what we have to do, and play to win.”