Despite admitting his team felt its star striker's absence, the trainer still praised the side's efforts and their season after securing a win against Pescara
With the 26-year-old sidelined through suspension, Gokhan Inler, Blerim Dzemaili and Goran Pandev grabbed the goals against the basement boys.
And while admitting the team was "anxious" without their talisman in the first half, Mazzarri praised the resolve displayed by his men in the latter stages of the match.
"Tonight we took an important step towards the Champions League," the Italian acknowledged to reporters after the match. "We knew it would be a tough game.
"Cavani is certainly not a bad striker so it's normal we missed him, but I was still sure we would be able to do well without him. We are not dependant on Cavani, and I know what the rest can give.
"I liked the attitude of my players. We struggled to get past Ivan Pelizzoli which made my men anxious, but the first goal was fundamental to unlocking Pescara."
Though Napoli began the campaign as title contenders, they have fallen eight points off the pace from front-runners Juventus, with the Turin giants still boasting a game in hand.
But Mazzarri was adamant this season can remain a milestone in the club's history.
"We recovered after a brief decline. Do not forget that we did better than last season. Winning direct qualification to the Champions League is equivalent to the Scudetto for us," he added.
"I'm reluctant to talk about next season, but I know the team can play at the same level across domestic and European competition. I will talk about my future at the end of the season.
The 51-year-old's contract is due to expire in June, although there are rumours club patron Aurelio De Laurentiis is ready to offer his coach a three-year extension.