But the reality, however much it hurts, is that Chelsea could hardly have made a more unconvincing start to the defence of their crown, on or off the pitch.
A Community Shield defeat by Arsenal was shrugged off as irrelevant, but something looked seriously amiss a week later in a fortunate 2-2 draw at home to Swansea City in which keeper Thibaut Courtois was red-carded.
That poor display was overshadowed by Mourinho’s removal of club doctor Eva Carneiro from bench duty after describing her as “naive” for tending to Eden Hazard — leaving Chelsea temporarily reduced to nine men.
Worse was to follow on Sunday, though, as Mourinho suffered his joint-heaviest defeat as a Premier League manager.
A listless display at City’s Etihad Stadium, particularly in the first half, allowed Chelsea’s main title rivals to steal a march and move five points clear.
The biggest bombshell, however, was long-term captain and defensive colossus John Terry being substituted at halftime for tactical reasons — the first time Mourinho had ever taken his trusty skipper off in the heat of battle.
The only good news on Sunday was the signing of left back Abdul Rahman Baba from Bundesliga club Augsburg — a welcome recruit after a summer in which Chelsea failed to significantly upgrade last year’s model.
So dominant last season when cruising to the title, Chelsea have looked under-cooked so far.
Not since 1998 have they failed to win either of their opening league games and while a five-point deficit on City with 108 more points to play for is no crisis — a return to form cannot come soon enough.
Yet Mourinho was having none of it after goals from Sergio Aguero, Vincent Kompany and Fernandinho sent City top.
“3-0 is completely fake,” Mourinho told reporters.
Speaking to Chelsea’s TV channel later, he added: “In the second half we controlled every aspect of the game.
“Then one corner, one mistake and 2-0. The best team in the first half won and the best team in the second half lost.”
Terry’s position in the team will dominate the week ahead as Chelsea prepare to face West Bromwich Albion.
“I had to decide on John or (Gary) Cahill because Zouma is the fastest player we have in our defensive line,” Mourinho explained of his decision to hook Terry.
“The point was not to bring John out but to bring Zouma in. I wanted to have my fastest player on the pitch.
“I’m the one that plays John every game, made him captain, brought him back from a difficult situation with other managers.”
(Editing by Ed Osmond)