The Blues suffered a humiliating 6-0 defeat to table-topping City at the Etihad, just two weeks on from their 4-0 drubbing at the hands of Bournemouth.
And the result which marked their heaviest defeat in nearly three decades has the Italian admitting there's cause for concern as his distinct 'Sarri-ball' playing style that earned him plaudits with Napoli, has been found wanting in the English top-flight.
"I didn't see my kind of football (against City)," he said after the game, as per The Telegraph.
"At the beginning, it worked. So now we need only to understand the reasons why at the moment it isn't working. We need to understand the reasons."
Sarri added: "It is not easy. At the beginning, we played better away than at home. Now we are playing better at home than away.
"Something is changing. At the moment I am not able to see the reason but I have to work for this because my target is to play my football, not to change another football because at the moment we are playing another football."
Sarri did not shake the hand of his opposite number Pep Guardiola at full-time but insisted he was merely eager to return to the dressing room.
He added: "I didn't see him at the moment but of course as usual I will go to say hello to him later as usual."
Guardiola, too, played down any speculation of a rift as he said: "I spoke with (Chelsea assistant) Gianfranco Zola. (Sarri) didn’t see me. I have a good relationship with him so no problem."
The Spaniard empathises with the scrutiny Sarri is under and believes the former Napoli coach needs time to implement his ideas.
Guardiola added: "People don't understand how difficult the first year can be. Mine was difficult too. People expect with a new manager and buying players it comes immediately, but it needs time."