How bad is too bad? What level of defeat forces a club to change its long-term plans? Is there even a long-term plan at Chelsea? Chelsea’s worst defeat in 28 years cannot but lead to serious questions and all precedent suggests those inquiries will end with the departure of the manager, Maurizio Sarri.

There always seemed something a little uncomfortable in Chelsea’s appointment of Sarri. This, after all, is an impatient club that has thrived on chaos in recent years. Sarri is the 11th permanent or semi-permanent manager Chelsea have had in the 11 years since the end of the first José Mourinho era, and by far the most idiosyncratic.

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To appoint Sarri is to commit to a long-term plan, to a wholescale rebuilding of the squad. It is to accept there may be a downturn in results before improvement comes. Since Roman Abramovich bought the club in 2003 that has not been the Chelsea way.

For Sarri to work would take time and there have always been doubts as to whether he would get it – not least because, given Abramovich has instructed bankers to seek a buyer, there are no guarantees as to how long he will remain as owner. The failure to appoint a new technical director after the resignation of Michael Emenalo in November 2017 speaks volumes about the lack of long-term planning. But recent performances have raised a corollary issue: even if Sarri is given time, there are no guarantees he will be a success.

Pep Guardiola spoke in defence of somebody he regards as a friend, talking of the difficulty of imposing a philosophy and of how he struggled in his first season. But the situation is not directly comparable. For one thing Guardiola arrived at City having already won six league titles and two Champions Leagues. He was a proven champion; Sarri has never won anything.

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There are reasons for that, given how he has had to fight his way up from the amateur leagues, but he nonetheless represents rather more of a risk. Each defeat generates far greater doubts than Guardiola’s setbacks against Leicester and Everton in his first season at City did.

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For another, Guardiola came into a club that had been built for him. The chief executive, the director of football and several players had been gathered with a view to placing Guardiola at their centre. Chelsea had not even got round to sacking Antonio Conte when they gave Sarri the job of replacing him.

But the biggest issue is that Guardiola never suffered a humiliation like this. There were occasional tactical problems, usually centred on playing too high a defensive line without the requisite level of pressing, but it was possible to see a solution. There was never such a meltdown, never such a series of limp, confused displays as Chelsea have produced away from home this year.

Most troubling of all is the way that Jorginho, the one player who was signed to facilitate the transition to Sarri-ball, has become the biggest problem. Perhaps with other players around him he would be more effective as a regista. Perhaps, with more creativity elsewhere on the pitch, it would be less straightforward to shut him down. But there are basic defensive issues resulting directly from Jorginho’s presence: the second, third and fourth goals on Sunday stemmed from a void at the top of the box, something highlighted by arguably the best defensive midfielder in the league over the past three seasons, N’Golo Kanté,being on the pitch but not playing as a defensive midfielder.

The doubtful experiment seems increasingly doomed.