Kaka has rejected suggestions that he put his career at risk by playing at the World Cup.
The Real Madrid playmaker underwent arthroscopic surgery on his knee last week after a routine pre-season check by the club's doctors discovered he had a problem, and is now set to be sidelined for four months.
The surgeon who performed the operation, Marc Martens, indicated that it was a serious injury that could have ended his playing days.
Brazil international Kaka later revealed that he had been hampered by the problem during the World Cup but did not realise the extent of the damage to his knee.
However, Kaka does not believe the injury was ever as bad as Martens has described.
Speaking of Martens, Kaka said: "He is a great professional but he raised the alarm, he exaggerated a lot."
Kaka had a disappointing first year at Real Madrid last season and his Brazil team went out of the World Cup at the quarter-final stage.
The player also said he expected to be 'the best in the world again' under his new coach Jose Mourinho.