Juve sold a half share in the attacker to Parma last summer for €3.75m, but bought him back earlier this month for €11m.
“I hope that he can find some consistency in Turin,” the former Azzurri boss told Sky Sport Italia on Wednesday.
“It is clear that no player can be assured of a first team shirt, he must therefore show what he can do when called upon.
“Giovinco has grown up a lot, but he can still improve. He will become an extraordinary player.”