City scored four times in the opening 25 minutes at the Etihad Stadium and twice in the second half to inflict Chelsea's worst defeat since 1991, with Sergio Aguero getting a hat trick and Raheem Sterling netting twice.
"I don't know, you have to ask the club", said Sarri, who was hired after leaving Napoli.
"Yes. We played good, the first four times we arrived we scored".
It began badly as they were caught napping after just four minutes.
No-one is expecting Newport to spring a surprise of mammoth proportions, and looking at the sides remaining in the FA Cup, City will strongly fancy their chances of lifting it come May.
"At the moment I am not able to explain".
Manchester City made sure they returned to the top of the Premier League table in style by absolutely putting the visiting Chelsea to the sword. After three games in a week - Arsenal, especially Goodison Park and playing the way we played with this intensity and the desire and patience to find the right moment, the players were outstanding. At the beginning it worked, so now we need to understand the reason why at the moment it isn't working.
Aguero should have doubled the lead nearly immediately but remarkably missed from two yards. Silva had weaved through the area to set up a gilt-edged opportunity but the Argentina forward uncharacteristically poked wide.
Pep Guardiola's side should have been 2-0 up sooner though.
City's average positions showed just how high up the pitch Sterling played, allowing him to get in behind Azpilicueta while Aguero exploited the space between around Rudiger.
The prolific Argentinian joined Alan Shearer on 11 Premier League trebles as the champions returned to their ruthless best in a one-sided encounter at the Etihad Stadium.
Jamie Carragher was unsurprisingly brutal with his analysis of Chelsea's first half performance.
The City boss also claimed the scale of this win would only serve to make retaining the Carabao Cup harder.
Aguero was inches away from completing his 15th City hat-trick when he headed against the woodwork from a De Bruyne cross.
Sterling wrapped up a brilliant afternoon's work after substitute David Silva opened up the Chelsea defence yet again and Zinchenko picked out the England global.
However, City's brilliant 6-0 victory over Chelsea on Sunday sent a message to Liverpool about their own title hopes. Now we play better at home than away.