Kaka says AC Milan teammate Mario Balotelli can be "a champion" if he improves his mentality.
Balotelli is again underfire after last week's interview meltdown on TV.
Kaka said: "I think he's a great football player. He must push himself more and do things as a protagonist. He can become a champion, he has great talent and I'm delighted to have him as a friend.
"He is a boy who may lose his head, but if he focuses his mind and takes a bit of responsibility he can do well in Italian and international football."