The Pirates surely would like to have Pena, too – he probably wouldn’t cost much more than the salary he’s owed for the rest of the season, and despite his issues (primarily a low batting average), he’d be a big upgrade over Lyle Overbay.
Tim Dierkes of MLB Trade Rumors writes that Pittsburgh and Arizona are the only destinations that make much sense, so if the Cubs really do want to deal him, then I’m sure the Pirates will be all over this.
Some Pirates fans might not like that, given that they’d like the Bucs to pursue a higher-profile target like Hunter Pence or Carlos Beltran. But the Pirates would have to give up serious prospects for those guys. The prospect cost for Pena would be minimal. I’d honestly prefer someone like Pena to someone like Beltran, for that reason.