Former Brazil attacker Kaka has admitted that he had a "complicated relationship" with Jose Mourinho when the pair were together at Real Madrid.
Kaka rose to prominence with AC Milan before making the move to the Bernabeu in the summer of 2009.
The versatile attacker won La Liga and the Copa del Rey during his time in the Spanish capital, but largely struggled to show his best form for the club.
The now 35-year-old, who retired from professional football in the latter stages of 2017, has conceded that he simply could not work with Mourinho due to their contrasting styles.
"In 2009, I accepted the proposal of Real Madrid, but I was completely destroyed there because I could not give what I had given Milan, I was completely lost," he told UOL Esporte.
"Jose Mourinho was a difficult coach for me and we had a respectful but complicated relationship. When I thought he would give me a chance, I couldn't prove to him that I was in good shape.
"I trained, I fought and I prayed a lot, but having not received the confidence of the coach, I realised that I could not work with him. The joy I had was to receive a message when he left Real Madrid and said that I was one of the most professional players he worked with."
The 2007 Ballon d'Or winner finished his career in America with Orlando City.
