The Brazilian has heaped the praise on his club team-mate and does not think there is another player like him in the world today
The Portuguese was once again at his best in midweek in his side's 3-1 win over Barcelona in the Copa del Rey, scoring two goals on the night to make it 38 goals in 38 games all season.
And in light of his impressive displays, Kaka has lavished his team-mate with praise and does not believe there is any one like him playing in the world today.
"Cristiano is the most complete player we have in football today," Kaka told the press.
"The strength he has, he has the ability to decide a game is unlike any other.
"I will not compare with other players, but I see it everday and I know he has the ability and the strength."
Kaka also revealed the close relationahip he enjoys with the former Manchester United star.
He added: "It is nice have him as a team-mate and as a friend and I wish him the best in everything what he does.
"We have a very good relationship, not only on the field and off, and I've always said this."