The two sides are currently joint Serie A leaders on 19 points each, already four ahead of the chasing pack. They meet next Saturday.
"This is a game that will be good for morale, but only at the end of the season will we get a clear idea of all the results and see where we are," Mazzarri told the Corriere dello Sport.
"We never said that Napoli were the anti-Juve. All we want to do is continue along our own path.
"I love a challenge and sport means every match is like a Cup Final for me. That is how I get fired up for each test."