He had a great career starting from Lille to Chelsea to Real Madrid. Although he didn't play much in his late career, his Chelsea days and national team performance were pretty good. For some reason he couldn't show same performance in Real, maybe that was because of his 100 million Euro transfer fee. Expectations were a lot higher for him. Actually he's still young and can play at least two more seasons at highest level but it looks like the football is over in his head. If he really wants to retire, I wish him success for the rest of his life.