AC Milan ace Kaka insists there's no serious problems over his knee injury.

"I know there is lots of concern over my injury but this story has been running for over a year," Kaka told La Gazzetta dello Sport.

"There has always been something that stopped me from listening to my body in recent times.

"For example, the knee would be painful but we had a European Super Cup to win, and then I wanted the Ballon d'Or and then the games in Yokohama. It kept going like that until I had to stop."