Kaka will face Ronaldo in the Champions League semifinal first leg between AC Milan and Manchester United on Tuesday.
Kaka told Record: “Ronaldo plays in a team which is having an extraordinary season. He is one of the symbols of Manchester United, has incredible talent and has every chance of still astonishing us all over the next few years.
“It would be beautiful to be part of a team full of excellent players. And it would be equally beautiful to one day play together with Cristiano Ronaldo.”