The veteran does not believe that there is a clear favourite for the Italian curtain-raiser, having been impressed with the way both clubs have performed during pre-season
The Partenopei earned the right to contest the first official title of the new Italian season by defeating the Serie A champions 2-0 in the Coppa Italia final in May.
It was Juventus' only competitive defeat of the campaign, and Zoff does not rule out the possibility of another victory for Walter Mazzarri's men.
"Napoli and Juventus are on equal ground in the Supercoppa Italiana," Zoff told Tuttomercatoweb. "Both clubs are doing great and are well established.
"Looking at their pre-season matches, both sides are doing very well. Juventus have invested a lot of money, they will play in the Champions League.
"Napoli, however, have a very solid foundation, the same coach, and players who have been playing together for years.
"Juventus may have some problems in defence, but it is hard to predict because Andrea Barzagli and Lucio are two good players and they can play well.
"If Napoli signed Federico Balzaretti, he would be a great addition to the team. He can play in several different positions and he has a lot of experience."