It is likely the former World Player of the Year will become surplus to requirements once the season gets underway.
Mourinho told AS: "If Kaka stays I would be happy and I am happy if he wants to go. In football it is normal that the players play where they want.
"He is a very good footballer and prepared to be at his maximum level. If he decides to stay, then perfect. If he goes, that's perfect too but we are not going to give him away for free. Those that want him have to pay for him."