Gregerson is drawing more interested than closer Huston Street, because not only are his numbers better, but he's owed less than fifty percent of what Street is owed. Gregerson is 4-5 with a 2.98 ERA in 46 appearances. With a 1.03 WHIP, Gregerson also is one of the best setup men in the game.
The Padres are looking for "controllable young pitching" in return for Gregerson, as they currently rank 26th in team ERA (4.24). Gregerson is a very good relief pitcher, and could be a nice consolation prize for teams who missed out on Francisco Rodriguez when he was dealt to the Orioles.
I believe that the Tigers will make the biggest push for Gregerson, considering how much they've valued relievers in this trade market. Gregerson would be able to solidify a bullpen that has plenty of issues this season, and could help them make a run into October. Detroit already has had their eye on Gregerson, as they reportedly offered starting pitcher Rick Porcello for the reliever.