Even by settling for a 0-0 draw in the first leg in Spain three weeks ago, Mourinho signalled that he is a coach who has failed to evolve with the modern game.
Apart from a raucous corner behind David de Gea's goal where the Sevilla supporters were housed, the famous stadium was suddenly bereft of belief, the tension that had preceded Ben Yedder's introduction replaced by despair.
"I told you yesterday that it would be disappointment if we would lose the match", the United boss said.
"I don't want to make a drama of it".
"I know this has happened at Manchester United before, because I have sat in this chair as manager of Porto and of Real Madrid".
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Ben Yedder, a former futsal player for France, moved onto eight goals in this season's competition and he missed a chance for a hat trick as United's defense fell apart in the latter stages.
"In the second half we were more clinical with Ben Yedder, he made the difference today".
Indeed, of Sevilla's 10 efforts on goal in the first period only one weak Muriel effort forced De Gea into making a save. We had risky situations in the first half, a good start in the second half and chances to score.
Paul Pogba is another who has missed a number of fixtures with a small problem and Mourinho has admitted he still remains a doubt for the Champions League tie.
Minutes later it was Sevilla's turn to breathe a sigh of relief, as Lukaku turned provider for Lingard this time, but the outstretched hand of Sergi Rico tipped the Englishman's shot around the post for a corner that would ultimately come to nothing. The Belgian flashed the first over from 20 yards after a good one-two with the winger, before Sevilla defender Langlet did well to block his second attempt on the edge of the six yard box following a risky ball in from Lingard. He collected Pablo Sarabia's cross and cut past Marcus Rashford, only to be denied by a thumping Eric Bailly tackle. "We are not the only team that invests money in players".
Ben Yedder put the visitors in front with a low finish just 87 seconds after coming off the bench in the 72nd minute and scored again with a header off the bar four minutes later.