It doesn't sound like Paul Maholm is coming back:
Management continues to seek to add to its rotation, but any additions probably will come from nonroster invitees or means other than a high-profile free agent ...
Neither side is closing the matter, but the Pirates seem largely set with their roster.
Also (via MLBTR), the Pirates have reportedly shown interest in reliever Dan Wheeler, but are unwilling to give him a major-league deal ... which of course makes sense, because they don't have any particular need for another righty reliever at the major-league level. Wheeler allows way too many homers, but he still deserves a major-league deal, so my guess is that he'll be headed elsewhere.