No complaining. No moaning. Just what - as the manager stated in the aftermath - he was "trying, trying, trying" to do under the Old Trafford floodlights.
Against Tottenham, United were aggressive, expansive. They played in the best of the club's traditions. Mourinho's tactics were spot on. In that opening half, the only thing to rue was the scoreline. The goal didn't come. But the place was heaving. The manager had inspired his players - and they in turn, the fans.
But then, after the break, this summer caught up with them. Those at the back were found out. Individual errors. In key moments. Even instances. For all the attacking intent, the difference between a good defender and a great one was laid bare.
A better, more experienced centre-half isn't allowing Harry Kane to sink him for Tottenham's opener. A stronger, more decisive player is cleaning out Lucas Moura before he scores his first. And Chris Smalling, for the Brazilian's second, well... there are reasons why Gareth Southgate didn't take him to Russia.
Over his 27 years in charge, Sir Alex Ferguson thought nothing of breaking transfer records on centre-halves. From Gary Pallister to Jaap Stam and Rio Ferdinand, huge money was spent. Many at the time labelled it crazy money. But this was the Fergie Way. If United were to play attacking, expansive football, they were always going to give up chances to the opposition. His defenders simply had to be better than the strikers they were facing. A world class goalkeeper and two top class centre-halves. This was the foundation on which Ferguson rebuilt Manchester United.
On Monday night, Mourinho tried the same. He has the keeper. He has the attack. But as is common knowledge now, that experienced, quality centre-half never arrived. And didn't it show against Spurs...?
This is what Mourinho tried to get across to the giggling hyenas in the post-match presser. United can play attacking football, yes. But it'll mean more openings at the wrong end of the pitch. One way of quickly short-circuiting that weakness is by finding better defenders - which United failed to do this summer.
Yes, Mourinho has seen Eric Bailly and Victor Lindelof arrive. Just as Jurgen Klopp oversaw the deals for Ragnar Klavan and Joel Matip. Yet in contrast to United, that didn't stop Liverpool 'doing a Fergie' and making Virgil van Dijk the world's most expensive centre-half. As for Loris Karius and Alisson Becker... well, we won't bore you going over old ground.
Then there's Manchester City and - as Mourinho has pointed out in the past - Pep Guardiola's keeper fixation. England's No1 Joe Hart (who, like Smalling and Phil Jones, has a couple of league winner's medals in his cabinet) was discarded. Claudio Bravo was signed and dumped. And now it's Ederson who is Guardiola's first-choice. It's no coincidence that City and Liverpool are early title favourites this season.
"He just needs to go with what he has," one former United player from the Fergie era told Tribalfootball.com last night. "I don't think he knows his best back four. But he needs to make a decision about who they are and stick with it for a good month or so."
Sound advice. In other words, get the defence right and the rest will take care of itself.
On Monday, Mourinho played it the right way. As he has since the market shut. And for all the hand wringing we're seeing in the press this week, the message has been received by an appreciative board.
Against Spurs, Ed Woodward, the club's vice-chairman exec, saw it all play out before him. He knows not finding that centre-half has let his manager down. Mourinho is "trying, trying, trying", but for an expansive game to be successful, he needs a better back four. Woodward could see that on Monday, which was why he made a beeline for the manager before his now infamous presser.
3-0 at home looks terrible on paper. And it was a career low scoreline for the Special One. But there was more to Monday night than the result. 45 minutes of "trying, trying, trying" the United Way has won the manager support from the higher ups.
If he wants the board to rethink their transfer policy, this was the way to do it.