Calderon, who was president between 2006-09, thinks the Spanish lockdown-hit finances at Real will mean they are unable to prise the Egyptian from Anfield.
Calderon told ON Time Sports: "He is a great player and a goalscorer. He helped Liverpool by giving his best, but I don't think they will let him go.
"It is expected that, if they were to think about it, they would only let him go for a lot of money.
"Salah is a great player with fantastic potential, and any club wishes to acquire such talents, but for Real Madrid I do not think they have the financial means to sign Salah."