Juve have won their opening two games of the new Serie A season.
Zambrotta told La Gazzetta dello Sport: "It's a great start, the best way to begin, and when you win, things go well, especially before a break when you have time to work. I saw it better against Parma, but against Genoa it was a bit more difficult."
On Lois Openda and Edon Zhegrova, he also said: "They're excellent signings. For financial reasons, they preferred Openda to (Randal) Kolo Muani. He's younger and did well at Leipzig: he's quick, fast, and versatile because he can play as a second striker.
"Zhegrova, even though he's been sidelined for about nine months, has quality and has the opportunity to work on regaining his fitness and getting into (coach Igor) Tudor's game.
"He targets his man, dribbles, and creates superiority: but he needs to get back to 100%."