Perhaps Maurizio Sarri really can't motivate these Chelsea players. This was the sort of performance that gets managers sacked.
Patience is hardly one of Roman Abramovich's virtues and the Chelsea owner's fury at this witless, spineless surrender will probably have been amplified by the reopening of old wounds given the manager who inflicted the club's biggest defeat for 28 years was the one he coveted above all others.
Whatever Sarri-ball is, it was a world away from the football of Pep Guardiola and his mesmerising Manchester City side.
Sarri said his biggest worry was not his job, which he suggested was "always at risk", but trying to figure out why his team are such a rabble. He seemed lost in his own thoughts as he disappeared down the tunnel at fulltime, having forgotten to shake Guardiola's hand.
Yet the Italian should know it did not end well for Luiz Felipe Scolari or Andre Villas-Boas at Chelsea in similar circumstances.
It was 10 years ago on Sunday that Scolari was sacked by Abramovich, seven months into his first season, following a goalless draw at home to Hull City, with Chelsea fourth, two places higher than Sarri's side.
Villas-Boas lasted until the March of his debut season at Stamford Bridge before the axe swung with Chelsea fifth.
Like Sarri, Scolari and Villas-Boas failed to win over the Chelsea players with their
methods. Like Sarri, they were stubborn in their beliefs and paid a heavy price. Is history about to repeat itself a third time?
City were 4-0 up when their supporters broke into sarcastic chants of "You need Mourinho" in the 37th minute and, watching the way Chelsea downed tools at the Etihad Stadium, only 11 days after a pasting at Bournemouth in their previous away outing, it is hard to escape the feeling these players have stopped listening to Sarri as they did Jose Mourinho in late 2015.
Publicly admitting he might be ill equipped to motivate them after the 4-0 defeat to Bournemouth was an own goal from Sarri but they blow like the wind, these Chelsea players, clocking off at the first sign of a kink in the road. If Sarri goes, whoever replaces him may have his work cut out. But the former Napoli coach really is not helping himself.
It was one of those minor mysteries when the fourth official's board kept going up and Jorginho's number was never called. He was by no means the only guilty party — this was a risible collective failure.
But quite how the Italy midfielder remained on the pitch after such an apathetic display that not only reinforced his physical limitations but also raised questions about his mentality was baffling and pointed again to the blind spot Sarri seems to have over his compatriot.
How long before Sarri accepts that Jorginho, for now at least, is floundering and central midfield needs reconfiguring? N'Golo Kante looked as lost as anyone in that more advanced midfield position Sarri keeps insisting he plays.
In just seven weeks, there has been a 12-point swing between Chelsea and a resurgent Manchester United, who now occupy fourth.
Chelsea can't afford to miss out on the top four a second successive season. There are similarities between the way Sarri started with a bang at Chelsea and Guardiola at City, before problems set in, but the similarities end there.
Guardiola knew his tactics would take time to register but there was a discernable plan, he knew he would get the signings he wanted and retain his best players. Can Sarri say the same at Chelsea? Guardiola also had his squad firmly on side. Motivation was not an issue. Moreover, he had the complete faith of his employers.
Abramovich's faith in Sarri is about to face its fiercest test.
- Telegraph Group, UK