As initially broken by Craig Grialou on Twitter, subsequently confirmed by Nick Piecoro in three separate tweets, and first FanShot'ed on the 'Pit by Clefo the D-backs have finalized their Opening Day roster. The last remaining bullpen spot to left-hander Wade Miley, with Takashi Saito heading to the 15-Day DL and Mike Zagurski being outrighted to Triple-A Reno. With the optionings of left-handers Patrick Corbin and Tyler Skaggs as well as the outrightings of catcher Ryan Budde and infielder Cody Ransom last night, that leaves Arizona's active roster at exactly 25 players. Details on exactly what went down and what to expect over the first few weeks after the break.
The first hint of there being a bullpen spot up for grabs came when Saito reportedly tweaked a calf muscle yesterday during warm-ups - the official diagnosis is a medial right calf strain. With the right-hander unavailable for the first week-and-a-half or so of the season, the potential to carry three left-handers in the bullpen - a possibility that had come up previously - further materialized. That said, Saito isn't expected to be shelved for long, with Piecoro reporting that D-backs manager Kirk Gibson hoping to have Saito back as soon as he is eligible to come off the DL on April 15 (Saito's DL placement can be made retroactive to his most recent appearance).
That means that whoever made the club in Saito's place likely isn't going to be around for long, barring another relief injury. I'm speculating here, but perhaps Arizona felt that this was the best time to sneak Zagurski through waivers, as his outright assignment required doing this and thus exposing him to all 29 teams. Combined with Arizona's desire for some length in the bullpen, as noted by Piecoro, and the door was opened for Miley to make the club. Miley has minor-league options remaining, so he can be regularly shuttled between the big leagues and Triple-A Reno if Arizona is in need of a left-handed reliever.
This is even further speculation on my part, but this could indicate the beginning of a significant shift in long-term role for Miley as a D-back. After starting seven games for Arizona in 2011, the left-hander may be moving into a permanent relief role for Arizona, as prospects Trevor Bauer, Tyler Skaggs, and Patrick Corbin - in some order - appear to have a stranglehold on the sixth, seventh, and eighth spots on the organizational starting pitching depth chart. Miley's projection as a starter in the long-term was uncertain, and with so many highly-regarded prospects knocking on the door of the big-league rotation, this could be how the organization seeks to utilize Miley's left arm from here on out.
I would also guess that this sets the table for us not seeing Zagurski in the big leagues until late in the year (i.e. when rosters expand) or until there's a long-term need/opening for him. Craig Breslow, arbitration-controlled only through 2013, is slated to make $1.795MM in 2012 and north of $2MM next year. If Breslow under-performs in 2012, the D-backs could want to have cheaper, controllable left-handed options available. Until there's a more permanent need for a southpaw, the ability to freely shuttle Miley between the majors and minors for a few spot LOOGY appearances is a benefit that could outweigh the likely-minimal differences in value over a few innings between the two southpaws.
As a final point, it's somewhat surprising to see Arizona sneak Zagurski through waivers, and good timing by them in knowing to do so now. I was fairly surprised by this (shameless Twitter self-link), as was Nick P, given what scouts were saying about Zagurski and the relative demand for left-handed relief pitching throughout the majors. Between Joe Paterson, Breslow, Zagurski, Miley, and even Patrick Corbin, the D-backs are flush with left-handed relief options - a far cry from the not-too-long-ago days of throwing Jordan Norberto out there and hoping for the best (that he would throw strikes...). Kevin Towers is proving his reputation for bullpen building to be on point.
Here's a final tally of the D-backs Opening Day Roster: