The 50-year-old is under no illusions as to the calibre of team the Partenopei will face in Sunday's final, while he believes his side paid the price for competing on three fronts
The Partenopei won many admirers for their positive showing in this season's Champions League, but their run to the round of 16 in the competition has arguably come at the cost of poor league form, which saw them eventually finish fifth.
However, they now have a Coppa Italia final to look forward to, and while he felt his team struggled to compete on all three fronts, Mazzarri expects Napoli to face a focused Juventus outfit on Sunday, despite their recent title success.
"The Bianconeri have more experienced players and are under less pressure because they have already won [the Serie A title]. They are the favourites" he told reporters at a press conference.
"For us, however, it is an event. For the first time ever, my team has been playing in the Champions League, and I am convinced that if we had not competed on three fronts this year, we would be at least 13 points higher in the standings."
Ezequiel Lavezzi's future has been the subject of much speculation since the end of the season, but Mazzarri maintained: "[Lavezzi] has worked perfectly during the week and is in great shape."
Napoli will be gunning for their third Coppa triumph in history, and their first since 1987.