With less than 18 months to run on his contract, Mbappe has been linked with a summer move to Real.
But Perez told El Chiringuito: "They tell me on the street, 'Presi, sign Mbappé!'. I say 'calm down'.
"Madrid need a change and I'm not talking about Mbappé. We have won many things, but we have to move and recover the illusion. It is not easy with the current situation, but I am in that job.
"I have not spoken with Mbappé, I do not know if he wants to renew. I don't know, I haven't talked to him for years, I don't know more than what I read in the newspapers.
"I do everything possible so that Madrid does not lose its rightful place. But it is true that we entered 900 million and now we enter 600."