The Old Lady are facing a battle to qualify for next year’s Champions League.
Melo has been under fire following his move to Juventus in the summer.
He told Sky Sport 24: “I am doing well with Zaccheroni. I have improved.
“Aside from the knock out suffered against Palermo, we are now starting to win.
“We expect a difficult match against Fiorentina. They are a very good team tactically but it’s a game that we have to win because we are Juventus and Juventus always have to win.”
He added: “Sure, it will be special to return to Florence.
“It’s a city that I will always remember and carry in my heart. Florence gave me everything: the Brazil team and… Juve.”