The ex-France striker, 33 and now playing for Hercules in Spain, spent a decade in Turin, becoming the club’s top foreign scorer of all time.
The Italian giants have fallen on relatively tough times though, and Trezeguet feels the players’ standards have dropped.
"They must remember what Juventus is," he told Tuttosport. "I would take the players into the trophy room to give them a sense of this history."
He added that, in order for Juve to return to former glories, the board should appoint proven winners both on and off the pitch.
"Juventus need to sign three champions who are used to winning things, not eight who are happy with fourth place," he said.
"Mourinho is the number one. Luigi Del Neri works hard, but (Juve president Andrea) Agnelli knows that a Ferrari needs a certain type of driver."