Milan coach Max Allegri is chasing his former Cagliari star.
"He'll only leave if everyone is satisfied with the eventual offer," agent Stefano Zambetti said.
"It's not that Andrea wants to leave Cagliari, but he cannot but be happy with the interest of a team like Milan, even if my client is happy in Sardinia.
"If the President is open to negotiation and Milan propose to buy the player then we could talk about it.
"I will stop by repeating that Andrea is very happy in Cagliari. We will see what developments arise from here until the end of the transfer window."