The 36-year old midfielder has been released by AC Milan after his contract at the San Siro expired and the Hammers are keen to bring him to East London.
North America's Major League Soccer are also showing considerable interest in luring the former Italy international across the Atlantic.
His agent, Moreno Roggi, said: "Obviously Massimo wants to continue playing. There are some negotiations in place and we are evaluating every type of proposal.
"His preference would be overseas clubs, but if an offer did come in from an Italian side, we would not ignore it completely.
"At this moment we are in talks with West Ham, while we have already ruled out Major League Soccer."