City welcome Napoli to the Etihad Stadium having plundered 29 goals from their opening eight Premier League matches, while Sarri's men boast a 100 per cent record in the Italian top flight, having scored 26 times.
Nevertheless, the former Empoli boss left a pre-match news conference in no doubt over who he views as favourites for the Group F encounter
Napoli lost 6-2 to eventual winners Real Madrid on aggregate in the round of 16 last season but Sarri suggested Pep Guardiola's in-form team could represent an even tougher opponent.
"The feeling I get watching Manchester City play, I didn't even get watching Real Madrid last year," he said, with Napoli three points shy of City heading into matchday three on account of their group-opening defeat at Shakhtar Donetsk.
"I always felt my team could give opponents a hard time, but this time I think Man City are a formidable team.
"But if we want to play at a certain level, we have to do it in important matches and aim at achieving results."
In terms of his research on a City side who have scored 17 times in their previous three Premier League home games alone, Sarri joked: "I watched a few matches. I didn't want to watch all of them because I didn't want to get depressed.
"I think Man City are by far the strongest team in Europe at the moment."
Nevertheless, the 58-year-old – who has progressed from splitting obscure coaching posts in Tuscany with a day job as a banker to the top tier of European football – is unlikely to deviate from his own swashbuckling approach despite the prospect of a City onslaught.
"I would like to die a sudden death if I have to, not a painful slow death," said Sarri, whose pre-match comments provided something of a marker for his players.
"When you play a tactical, savvy and gifted team like Man City, who are well prepared from a physical point of view, you have to be careful not to overthink things.
"We have to focus on our game. They could be superior to us on the pitch. From the technical point of view and speed they might be slightly better.
"All I am asking us is not to be fearful, to respect our opponents but not to fear them. Fear paralyses you and prevents you from doing your best.
"I want to see 11 players who believe in themselves. It may be impossible but maybe we have to be a little crazy. If we do not have this crazy belief then what is the point?"