The left-back crossed the derby divide in a €24 million move announced Wednesday. Here is a look at others who left the Rojiblancos for Los Blancos
ANALYSIS
There is no love lost between Atletico and Real Madrid. Anyone who has attended a match between the Spanish capital's two top teams will soon witness the animosity between the clubs - and that makes moving from one to the other a complicated matter.
In recent years, there has been a "non-aggression" pact ruling out such switches anyway and that stopped Sergio Aguero from swapping the Vicente Calderon for the Santiago Bernabeu back in 2011.