Ibra and Milan announced their agreement last night.
Asked about Poland striker Piatek, Bia told TMW: "We have to do a lot of evaluations, on the role that Ibra will have on the field. Now the Polish is not worth 40 million, sorry, and at the moment he is a failure.
"But in my opinion, put in the right conditions the Piatek seen in Genoa could return. Maybe with Ibrahimovic nearby he has less pressure."