Last May, the Yankees bullpen was forced to adjust. Mariano Rivera’s injury forced a premature glimpse into an inevitable future, and the Yankees filled the void with a veteran who’s since left for Washington. Now Rivera is back, but he’s brought only a sense of temporary security. Much like the rotation, the Yankees bullpen has been filled by a capable and potentially strong group of pitchers, but that group has left significant uncertainty for 2014 and beyond. There are young relievers on the rise, and the Yankees might have jobs for them in the not-so-distant future.
 Mariano Rivera, Joba Chamberlain, David Aardsma, Boone Logan (signed through 2013)
Dave Robertson (second year of arbitration)
The Yankees have five relievers who I believe are locked into big league jobs this season. Clay Rapada might be a sixth, but he’s certainly not as entrenched as the five listed above. You might have noticed that four of the five will be free agents at the end of the season. For the time being, this group offers solid depth with some undeniable risk. Rivera had knee surgery last year; Chamberlain and Aardsma each had Tommy John in 2011. The best-case scenario for those three is awfully good, but it’s hard to know how likely those best case scenarios might be. Logan became more of a workhorse than strict lefty specialist last season, and he could fill the same role this year if Rapada is back with the team. The key here just might be Robertson, whose walk rate dipped considerably last season and who no longer has Rafael Soriano as a safety net. The loser of the David Phelps/Ivan Nova rotation battle could find a spot in the bullpen, as could experienced, fairly young guys like Jim Miller and Cody Eppley.
 On the verge
Mark Montgomery has only one full season of pro ball on his resume, but he’s already put himself into the big league discussion. Maybe not out of camp, but certainly at some point during the season, Montgomery could most certainly become an option in the Bronx. His fastball/slider combination has generated 150 strikeouts with 35 walks through 92.2 minor league innings. He got to Double-A late last season and has drawn some comparisons to Robertson. Less flashy but slightly more advanced is Chase Whitley, a 2010 draftee who’s already logged 80.1 innings in Triple-A. He doesn’t have Montgomery’s massive strikeout totals, but Whitley gets groundballs and has routinely pitched two, three, even four innings at a time. He could get his first crack at the big leagues this season, but he’ll be fighting for an opportunity alongside fellow right-handers Eppley, Miller, Preston Claiborne and possibly Kelvin Perez. From the left side, last year’s Rule 5 pick Cesar Cabral could be an early summer option if his elbow has fully healed. Recent 40-man addition Francisco Rondon, waiver claim Josh Spence and returning Triple-A reliever Juan Cedeno add more immediate depth from the left side.
 Deeper in the system
Used to be that a farm system’s real pitching talent was limited to the minor league rotations. A young pitcher who’d already been moved to the bullpen didn’t have much future, but that’s no longer the case. The Yankees system is actually pretty deep with bullpen arms. The 2010 draft gave the Yankees Tom Kahnle (72 strikeouts, 0.98 WHIP, 2.45 ERA) and 2011 gave them Branden Pinder (67 strikeouts, 1.46 ERA, 2.79 ERA), each of whom spent last year with High-A Tampa — each was promoted to Trenton at the very end of the year — and each of whom has legitimate bullpen potential. Last year’s sixth-round pick was LSU reliever Nick Goody, who pitched at three different levels last season and had 52 strikeouts, with nine walks and 20 hits through 32 innings. He’s already touched High-A and could move very quickly. Lefty Jeremy Bleich and righty Graham Stoneburner are former starters who have moved to the bullpen after injuries. Both have ability, but both need to prove themselves all over again. The jury is still out on whether Pat Venditte is a legitimate prospect or a switch-pitching oddity, but further evaluation will have to wait until mid-season while he recovers from injury. Just like with the rotation, it’s hard to mention all of the edge-of-the-radar, lower-level relievers in this space, but I’ll save a spot for Dan Burawa, who earned an early invitation to big league camp that was cut short by an oblique injury last season. Still a name worth knowing.
On the move
There are legitimate pitching prospects who are developed as relievers, but there are still plenty of minor league starters who eventually find their way into the bullpen. It has long been wondered whether Dellin Betances — with his big body and inconsistent results — might be better suited to a relief role (I contend that, if he can’t throw strikes, he won’t be suited for a role period). Basically, any young starting pitcher has the potential to move into the bullpen eventually, but the idea becomes especially intriguing with the hard-throwers like Betances or Jose Ramirez or Gabe Encinas. Makes sense to keep them in the rotation as long as possible, but if the need presents itself — or it becomes clear that they don’t have the secondary pitches or durability for the rotation — the bullpen can always become an option.
What to watch
Of course there will be immediate interest in Rivera’s return, but Aardsma is also worth some attention. He’s still a bit of a Yankees mystery, having hardly had time to prove anything last season. His past success could make him a major factor if he’s on top of his game. My guess, however, is that most of the bullpen anticipation will center on Montgomery, whose minor league dominance suggests a potent late-inning force. As with any season, it’s worth watching to see which minor league starters pitch their way into bullpen before the end of the year.
Associated Press photo; headshots of Chamberlain, Robertson, Montgomery, Whitley, Kahnle, Pinder and Betances