Kaka, 28, who is in South Africa as part of Carlos Dunga's squad, has the highest regard for Liverpool and England skipper Gerro. "He is one of the few players in the world that has the ability to be a Madrid player," said playmaker Kaka.
Gerrard, 30, has yet to decide his future after Liverpool finished only seventh in the Premier League last season. With no manager appointed since Rafa Benitez's departure, Kaka told the Daily Star Sunday: "I would urge him to join Madrid.
"If you never play for Madrid, then there will always be something missing.
"There is no greater achievement than wearing the white shirt of Madrid.
"His next contract will be his last big one - and that's a big choice not just financially but about what you can win."
Mourinho tried three times to lure Gerrard to Chelsea when he was boss.
And Kaka added: "I am sure Gerrard respects Jose a lot and Madrid would be the ideal move for him."