Juventus coach Alberto Zaccheroni insists Diego has the talent to be a Serie A star.
The Brazilian was on the scoresheet in Juve's victory over Bologna on Sunday.
Zaccheroni said: "Diego has to get used to the Italian League. He is an extraordinary trequartista. Alessandro (Del Piero) is the captain who takes the team in hand. He still seems like a little boy to me. He shows total application.
"I don't know how long this wonderful period of his can last: from what I see in training, I believe a while to come yet.
"We are on the right track, but Juventus's convalescence is not absolutely over. We still haven't consolidated anything. We play every three days. I haven't yet had the time to go into particulars."