Real Madrid president Ramon Calderon has hinted he would be prepared to sell Ronaldo to Milan, if Kaka was involved in part exchange.
Calderon pledged to buy Kaka as part of his election manifesto earlier in the summer, but Milan have been determined to retain the services of the Brazilian playmaker.
The Real chief is due to meet Milan officials on Wednesday and the futures of Kaka and Ronaldo are expected to be discussed.
“I will talk to Milan,” said Calderon. “I know they have already talked with the player and I don’t think that is right, but we are still prepared to receive representatives from any friendly club.
“We don’t want to get rid of him, but we are prepared to negotiate.
“If Ronaldo wants to leave then we’ll have to look for a solution. We don’t want money, we want something else (Kaka).
“Ronaldo told me before that he wants to stay and finish his contract here, but we’ll have to see what happens.”
Meanwhile, Milan’s chief officer Adriano Galliani reiterated the club’s desire to bring Ronaldo back to Italy.
Galliani said: “We have officially asked Ronaldo. There is already the player’s agreement, but now we must negotiate with Real Madrid.
“We asked him, now we will see what will happen.
“Should he arrive, it will be good, otherwise we will play with who we have, who are good, too.”