The Blancos chief insists the Italian champions must table a significant offer in order to secure the services of the want-away striker.
The Argentina international is said to be itching for a move away from the Bernabeu this summer, with the Bianconeri and Arsenal both understood to be keen on adding the 25-year-old to their ranks this summer.
The Italian champions are believed to be leading the hunt for the want-away striker, with club officials reportedly preparing to table a 22 million euro bid, but Perez has warned that such an offer would not even be given time of day in the Spanish capital.
"If Juventus are thinking about offering 30 million euros for him then it would be better if they don’t even turn up, because that will not be enough," Perez told Mediaset. "But we have not yet received any offers for Gonzalo and that is including Juventus."