Pep Guardiola was hailed as the best thing to happen to English football when he swanned into Manchester City at the start of this season and immediately swept all before him with 10 cultured victories in a row.
Yet if that all seemed too good to be true, City fans now know it really was. In the subsequent 15 matches in all competitions, Guardiola's team have won just four times. One of those was a stellar night against Barcelona but they have too often flattered to deceive.
If that was all worrying enough, Saturday's 4-2 defeat at Leicester City was positively alarming, a shambolic performance with a striking absence of the pass-and-move crispness of the best Guardiola teams and showcasing real defensive deficiencies.
It left City fourth in the table, four points behind leaders Arsenal, but they could be seven points off the pace should Chelsea beat West Bromwich Albion on Sunday.
It is far from a calamity for City but as Guardiola tried to explain away the defeat afterwards, there were hints that, after his triumphs in Spain and Germany, he is finding the manic puzzles of the Premier League rather harder to solve.
"I have tried to control games so we concede few goals in my career as a coach, and here I cannot do that, and I have to analyse why," he told reporters afterwards, promising to work overtime to put things right.
He has always said he would not dilute the way he goes about playing in the Premier League but asked if he would compromise on his philosophy, he said: "I have to improve to solve that, yeah, that's true."
There was also an intriguing exchange in light of City's fragility about his approach to on-field duels. "I'm not a coach for the tackles, so I don't train the tackles," he said.
As ever, though, Guardiola was protective about the performance of his players, saying: "I'm not disappointed with them."
Others are, though. Having been so far accorded in Manchester the respect his record and reputation as the world's leading coach deserves, there were signs in the reaction to the Leicester defeat that any fawning may be well and truly over.
The Manchester Evening News reckoned it had all been akin to "the worst days of (previous manager) Manuel Pellegrini last season" and made a withering observation: "It is not so much Messiah as simply mess."