Red Sox definitely moving towards deal for Hanrahan. Iglesias will not be in deal.— DKnobler (@DKnobler) December 22, 2012
If not Iglesias, then it's even more likely some B-prospect is on the way to Pittsburgh along with relievers to help the Pirates plug their bullpen holes. Potential prospects -- using logic, not sourcing -- are Brandon Jacobs, Drake Britton, Stolmy Pimentel, and maybe Bryce Brentz. Jacobs needs to be added to the 40-man roster next year in order to be protected from the Rule 5 draft, and both Britton and Pimentel are already on the 40. Since the Red Sox need to open up two spaces still just to get Mike Napoli and Stephen Drew on board officially, never mind to bring Hanrahan on board, someone or someones from the 40 need to be moved somewhere.
Brentz is a possibility if only because he's considered by many to be a second-division starter, not the kind of player the Red Sox tend to keep around from the farm. He might be their second-best outfield prospect, but that has more to do with the state of their outfield prospects after Jackie Bradley than anything having to do with Brentz. There's a lot to like about him, and it all point to a solid ceiling, but his floor remains cavernous and a real possibility.
Again, though, none of these players have actually been connected -- it's all speculation by those of us waiting around for the rumored trade to release some actual information.