Mendy, who made a substitute appearance in Les Bleus' disappointing Euro 2020 qualifying defeat to Turkey on Saturday, has been linked with a €50million move to the LaLiga giant after two seasons with Lyon.
The 24-year-old is expected to join Luka Jovic and Eden Hazard at Los Blancos as Zinedine Zidane continues an overhaul of a squad that disappointingly finished third in LaLiga last term and crashed out of the UEFA Champions League in the last 16.
Speaking on Monday, Deschamps revealed Mendy will indeed be the next player to pitch up at the Santiago Bernabeu.
"Ferland has had a spectacular growth," he said. "He was in Ligue 2 two years ago and he will be at Real Madrid next year.
"He has both feet and with us he has been good every time he has had to play."
The impending arrival of Mendy is also sure to spark speculation about the future of Brazil left-back Marcelo, with Sergio Reguilon and Theo Hernandez adding competition for the position.