Italy's famously volatile media were waxing lyrical about Napoli after they won their first two Serie A matches of the season, including a 3-1 victory over last season's winners AC Milan, and drew at Manchester City in the Champions League.
However, the tune changed completely after a 1-0 defeat at Chievo Verona was followed by a goalless draw at home to Fiorentina in the space of four days.
"I've heard people talking about Napoli in crisis," Mazzarri told reporters on the eve of the Champions League match at home to Spain's Villarreal.
"After two wins in the championship they talked about us as the side to beat and now it's a crisis. It goes from one extreme to the other and that's bad."
Mazzarri added the Champions League, where Napoli are taking part for the first time, would take precedence over Serie A.
"Things have changed this year," he said. "The priority is the Champions League and not the championship.
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