If Davide Zappacosta is your answer, you probably don’t understand the question.

Maurizio Sarri’s determination to live or die at Chelsea by his ‘Sarri-ball’ philosophy reached a new low here with the gradual rejection of his ideas spreading from the players to the stands.

Blues fans were already chanting “F*** Sarri-ball” and “you don’t know what you’re doing” before, at 2-0 down to a Manchester United side defending deep and refusing to be prised open, Sarri ignored calls for Callum Hudson-Odoi and switched one right-back for another.

In fairness, Cesar Azpilicueta had endured a torrid second half, terrified by United’s counter-attacking pace and Marcus Rashford in particular, but his substitution for Zappacosta also represented a doubling down of the dogma that has come to paralyse this club.

United did what Tottenham, Arsenal and others have done before them: detail an advanced central midfielder with the task of interrupting passing between Chelsea’s centre-backs and playmaker Jorginho while denying the latter space to play out from deep-lying central areas.

Juan Mata did what Dele Alli, Aaron Ramsey and others have done before them. Jorginho looked horribly lost at times as yet another midfield diamond nullified the home side after a briefly promising start.

United have rarely played in such a system and it is precisely the type of tactical tweak Sarri seems either unwilling or incapable of making to this ailing Chelsea outfit.

United interim boss Ole Gunnar Solskjaer told Standard Sport: “There’s different ways of stopping a team and they’ve got so many good players.

“Juan did a fantastic job between the two centre-backs and Jorginho. He ran his socks off, he stopped [David] Luiz when he had to, he stopped Jorginho when he had to and he ran up to [Antonio] Rudiger a few times so I thought his work-rate was phenomenal.”

The effect it had in giving United a foothold in this FA Cup fifth-round tie was also predictable, offering further evidence that Sarri either has to introduce fresh nuance to his preferred approach or the penny must drop this week in the most improbable fashion.

Finding a way past Malmo should be relatively straightforward given a 2-1 lead from the first leg of their Europa League last 32 tie but Sunday’s League Cup Final against Manchester City will have a few at Cobham shifting around uneasily already.

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City’s 6-0 Premier League win came just nine days ago and if United, outclassed by Paris St Germain last week, can win here with some degree of comfort, Pep Guardiola’s side must be itching at the chance to get at Sarri’s beleaguered players once again. Ironically, the mere existence of that cup final may help keep the 60-year-old in his job a little longer, however.

It would be a remarkable move, even for ruthless Roman Abramovich, to sack his manager just a few days before a Wembley showpiece, albeit if it is difficult to envisage a way they can win playing like this.

United are resurgent under Solskjaer and this was an acute reminder of just how much the mood and performances can change with someone at the help who possesses an intimate understanding of a club and its values.

There was a feeling that the shortened pre-season Sarri was given as the departure of Antonio Conte dragged on into July would compromise his efforts but in fact Chelsea started well before hitting troubled waters.

What has followed is a growing and sustained rejection of the course they are navigating. This group simply do not appear to believe in the way Sarri wants to play. They were not guilty of giving up, as could be levelled against some Chelsea teams in the past; indeed, they did not lack motivation as Sarri himself as previously suggested.

But there is fuzzy thinking, a scrambled style caught between what Sarri wants and what comes more instinctively to these players, something he aptly described afterwards as “confusing football”.

First half goals from Ander Herrera and Paul Pogba, who looked at his marauding best, gave United an advantage they rarely looked like relinquishing as Chelsea supporters gradually turned on Sarri in increasing numbers. It was a hostile atmosphere by the end, only offset by United’s jubilant away end who were, unsurprisingly, also singing about their manager but in far more complimentary terms.

Sarri said: “I can understand the situation and our fans because the result wasn’t good.

“We are out of the FA Cup so I can understand. I am worried about our results.”

Sarri continues to insist he does not feel under pressure — despite admitting “F*** Sarri-ball” is a chant he had not previously been exposed to — but it is hard to see a way back from this.

Malmo’s visit should offer some brief respite but City and then Tottenham await. Should Sarri see out the month, it will feel like something of an achievement. To do so, he needs to come up with some new answers — and fast.