Mazzarri refused to dwell on losing the title to the Bianconeri and instead outlined how much his team improved during this campaign.
"We earned 17 more points than last season, which says a great deal," Football Italia quotes the 55-year-old as saying.
"We ran into a stratospheric Juventus, so must focus only on ourselves."
The Italian has previously hinted that he may step down as coach at the end of the season, but refused to make any comment on his future.
"After the final game of the season with Roma, then I will talk to my president about the future," he added.
Napoli visit Bologna on Wednesday.