Mazzarri: It is too early to talk about Napoli's season goals
He held his first press conference on Friday after taking over from Rudi Garcia, who departed following Napoli's 1-0 home loss to Empoli.
Garcia took charge at Napoli in June after Luciano Spalletti resigned following Napoli's first Scudetto win since 1990.
The French manager was sacked after a lacklustre start to the season with Napoli 21 points behind leaders Inter Milan.
"It’s a tricky moment, so it’s not the right time to think about it (ambitions)," Mazzarri told reporters on Friday.
"The next match is the most important one, at the end of the season, we’ll make our assessments.
"We can’t think about the title if we don’t win games."
Mazzarri has returned to Napoli for a second spell in charge after he managed the team from 2009-13.
"I am thrilled, this is surely the best team I’ve ever coached," he said.
"Napoli is home to me. Napeolitans have always shown me love. When I left, my cycle was over."
Atalanta are fifth in the standings, one point behind Napoli.
"You can think of being stronger than the others, but it is difficult for everyone in today’s football," Mazzarri said.
"I am here to make the team understand that there are perils.
"The other teams are waiting for us with more attention, so we should underestimate nothing."
Atalanta's Gian Piero Gasperini said his side knew of Napoli's strengths.
"They are always a very strong team, one that dominated the championship last year," Gasperini told reporters.
"I expect the best from Napoli, but we are also in a good position in the league.
"For us it has always been a good match to measure ourselves, tomorrow we will certainly find out what level we are at."
