#4 Kaka – Real Madrid
He was probably one of the biggest let-down signings to have ever arrived at the Spanish club. Despite being a world renowned player, Kaka found himself falling out of favour due to various injury issues. He struggled to live up to his reputation at the Barnebeu and was soon leaving. PREVIEW FOR #3: The current Newcastle midfielder was once donning the Manchester United shirt. Back in 2009, Gabriel transferred to the Red Devils from Bordeux for 3 million. However, he went on to make only a handful of appearances for the club due to injury and the competition from his peers within the first team.