City are in negotiations with the Italian giants over the transfer of the Brazilian playmaker in a deal which, if successful, would smash the world record transfer fee Real Madrid paid Juventus for Zinedine Zidane in 2001.

Kaka's father will meet his son and City officials next week to discuss the move, with the Eastlands club thought to be offering the 26-year-old a £500,000 a week wage packet.

And Berlusconi admits his club would have to let the 26-year-old leave, much as they did with Andriy Shevchenko in 2006 when he moved to Chelsea from the Serie A giants.

"Nothing has been decided yet, but it is very difficult to make someone stay when he could earn a certain amount," Berlusconi said.

"Of course I would be upset if he leaves. Everything's still up in the air and it's very difficult to ask a player, who has been offered so much, to stay to respect his contract.

"I already told Adriano Galliani what I think, but my reasoning is clear.

"It's hard to say no to a lad who has a career which is not for his whole life and has the prospect of an income that is much superior to what he is getting at the moment.

"We can't increase a salary which is already at its maximum. Otherwise we would have to increase everyone's and frankly it's not possible, but I hope he stays.

"We have to look to our conscience and act like an older brother as we did with Sheva, who we couldn't say no to when an offer from Chelsea came in."

His words will do little to appease angry Milan fans, who have been protesting today at the San Siro, and are preparing a mass demonstration for tonight's Serie A encounter with Fiorentina.