Theo Hernandez will sign a six-year deal with AC Milan ahead of a 20 million euro move from Real Madrid.
The left-back, who spent last season on loan at Real Sociedad, will undergo a medical at the Italian club on Monday.
Everything is agreed between the two clubs and the player so once he completes his medical, an official announcement will be made.
This sale will take Los Blancos over the 100 million euro mark in terms of player sales this summer after the departures of Marcos Llorente and Mateo Kovacic.
Real Madrid also hope to receive a total 100 million euros more if they can sell Gareth Bale and James Rodriguez this summer.