Closer Joel Hanrahan is assured a spot, as are right-handers Jason Grilli and Chris Resop. Evan Meek, nonroster invitee Juan Cruz and lefty Tony Watson, although not sure things, seem well positioned to break camp with the team.
This assumes that the Pirates will go with a seven-man bullpen, of course, but that seems pretty likely. If indeed it's down to Leroux, McCutchen, Hughes, Igarashi and Moskos, the decision seems easy -- take Leroux. Igarashi has a good fastball but is otherwise just a bad pitcher, so you can toss him out right away. McCutchen is a fine player to have around, but he's not good enough to take north if there's a roster crunch, and he has an option left. Moskos is a mediocre lefty who posted a good ERA but a poor strikeout rate last year. That leaves Leroux and Hughes, and Leroux gets the nod there because he's out of options. Leroux was excellent down the stretch for the Pirates last season.
For more on the Pirates, check out Bucs Dugout.