The Brazil international is the subject of talks between Real and AC Milan while the clubs are in the USA.
"Kaka is suffering as he doesn't know if he can be the hero as he always has been and there is fear that he will fail. His head will not be focused until after August 31. He is a great professional, but it does not help when the mind is complicated.
"If he decides to stay, he will help us like last season when Angel Di Maria was injured or later when Mesut Ozil was out and Kaka was our 10. If he decides to leave, I'll respect his decision."