The right-back came through Los Blancos' youth-team ranks but insists ahead of Saturday's Champions League final that he is now Atletico Madrid through and through
The defender came through Los Blancos' youth system, making six Primera Division appearances for the Spanish giants before leaving for Osasuna - after a loan spell at Espanyol - and then moving to the Estadio Vicente Calderon in 2011.
However, despite his Real background, Juanfran insists ahead of Saturday's all-Madrid Champions League final in Lisbon that he is now Atletico through and through.
"I'm very grateful to Madrid for the years I spent there, how they treated me and trained me, but now I'm an Atletico Madrid player and I am aware I've been wearing the best colours," the right-back told Uefa's official website.
"Of course, matches against Real Madrid are different, they are more special, but all I want and all I think about, above all, is victory for Atletico - the past is behind me."
Atletico go into the final as the newly crowned champions of Spain, having claimed their first Primera Division title since 1996 courtesy of a 1-1 draw at Barcelona.
Juanfran, however, says that winning the Champions League would be an even greater achievement for Los Rojiblancos, who have only appeared in one previous final, in 1974, when they were beaten by Bayern Munich.
"It would be incredible, for me and my family," the 29-year-old stated. "They are proud of what I have done and what I am doing but, of course, being a European champion and being the best team in Europe is as good as it gets."