Iker Casillas has revealed he felt like a "puppet" during his final years at Real Madrid and has promised to disclose the reasons behind his departure when the time is right.
The Spain international made over 700 appearances in all competitions for Madrid between 1999 and 2015, before leaving the club for Porto following a number of difficult seasons.
"I had to decide between staying and being the puppet that people liked playing with," Casillas told XL Semanal magazine.
"I looked out for the interests of Real Madrid every single day.
"If I'd have looked after my own interests more we would've had a circus every day, especially in my final season.
"Someday I will tell you why I had to leave and when I write a book in 15 years, I will tell you."
Casillas' poor relationship with former coach Jose Mourinho was one of the main reasons behind Santiago Bernabeu exit and he has admitted it was not easy to work with the Portuguese coach after they fell out.
"That bad relationship [with Mourinho] divided people," he added.
"It was very uncomfortable because in the dressing room there were two people whose relationship was deteriorating."