Bullpens will have plenty of variability over the course of the year, there's really no telling who will end up making major contributions this season. Last year, the three best options ended up being John Axford, Zach Braddock, and Kameron Loe, and I didn't bother putting down any of the three for our preseason projections last year-- and in fact they threw a total of 7 major league innings in 2009, all by Axford. So despite that, I think the bullpen will be a bit more settled this year and I've narrowed it down to the 6 most likely to make an impact-- and I think anyone after these top 6 would probably be projected near replacement level, which is about a 4.5 ERA for a reliever, anyways.
John Axford
ZiPS: 69 IP, 3.62 ERA
2010: 58 IP, 2.13 FIP, 2.4 tERA, 2.48 ERA
Zach Braddock
ZiPS: 45 IP, 3.35 ERA
2010: 33 IP, 2.9 FIP, 3.15 tERA, 2.94 ERA
Latroy Hawkins
ZiPS: 41 IP, 3.95 ERA
2009: 63 IP, 3.97 FIP, 4.8 tERA, 2.13 ERA
2010: 16 IP, 3.95 FIP, 4.38 tERA, 8.44 ERA
Manny Parra
ZiPS: 152 IP, 4.84 ERA (as a starter)
2009: 140 IP, 4.88 FIP, 4.78 tERA, 6.36 ERA
2010: 122 IP, 4.5 FIP, 4.59 tERA, 5.02 ERA
Takashi Saito
ZiPS: 49 IP, 3.08 ERA
2009: 55 IP, 4.25 FIP, 4.07 tERA, 2.43 ERA
2010: 54 IP, 2.43 FIP, 2.19 tERA, 2.83 ERA
Kameron Loe
ZiPS: 115 IP, 4.62 ERA
2010: 58 IP, 3.71 FIP, 3.66 tERA, 2.78 ERA