That's according to Okdiario's chief pundit Eduardo Inda, while speaking on El Chiringuito.
Mbappe has a deal with PSG to 2022 and recent statements suggest he has no plans of extending it.
"At Real Madrid they believe that what Mbappé did this weekend was to launch a 'little letter' to the Blanca club. During these days there has been talk of the future of Zidane, that his days in Madrid are over," said Inda.
"At Real Madrid they believe that it is a message because Zidane is the one who has been negotiating in recent years with the player, who calls him regularly. He says if Zidane is not there, we will see what happens. The message is to say 'Zidane has to stay'."