The Yankee rotation began the 2014 season as their strongest asset. All five of their starting pitchers had the ability to end the year with top-of-the-rotation numbers. After suffering a tear to his UCL, Ivan Nova is likely out of the picture for this season, and not only does this put a strain on the Yankees' starting pitchers, but also their bullpen.
After the Spring Training competition for the fifth starter spot, the Yankees rightfully settled on Michael Pineda and sent David Phelps, Adam Warren, and Vidal Nuno into the bullpen. The three ex-starters haven't been without their faults, but they've also shown value in the right situation. With Nova likely to undergo Tommy John surgery, the Yankees will need at least one of these three bullpen arms to convert back to the rotation.
Warren has been the most effective of this group. He's pitched just 9.2 innings in relief thus far, but his velocity increased in these short outings. He's been very effective overall, and when David Robertson returns tomorrow, he'll probably be Girardi's third most trusted guy in the bullpen. Due to the lack of depth after designating Cesar Cabral and Matt Daley for assignment, Warren will likely remain in the bullpen.
Vidal Nuno made his first start of the season after the Yankees' doubleheader on Wednesday screw up the scheduling of the rotation. Nuno put together an impressive start against a less than impressive Tampa Bay offense. This offense did put together 16 runs on Saturday, but the Rays gave Nuno a number of easy outs. Nuno matched his pitches up well enough to earn six strikeouts in his 5.0 innings of work, and allowed just three hits and two walks overall. His four-seam fastball, changeup, and curveball performed well, but only one of Nuno's eight sinkers was a strike, and that ended up as a line drive. His slider was equally bad, and he didn't earn a single swing and miss on seventeen of those pitches. While Nuno is a tricky southpaw, he doesn't command a pitch that'll reliably earn strikeouts.
This leaves us with David Phelps, who's shown mixed results out of the bullpen this year. Phelps has the same repertoire as Nuno, however he throws harder and earns more swings and misses on his curveball and changeup. Phelps has also shown better command of his sinker, and can use it to induce ground balls when double play scenarios come up. Finally, Phelps also has 23 games of starting experience, something that Girardi values greatly.
Phelps may be the best candidate for the job, but the choice to keep him in the bullpen instead of the Triple-A rotation now adversely affects the Yankees. Phelps' pitch count in recent games has been 29 on April 16th, 15 on April 18th, and 16 on April 20th. Phelps is not stretched out long enough to start a game, and even given a long leash, he'd probably only hit about 50 pitches before getting pulled. The Yankees are notoriously careful with their young pitchers, and it would be surprising to see him immediately bounced back into the rotation. While Nuno is the most qualified to pitch out of the rotation at the moment, Phelps is probably Girardi's top choice.
Last season, Joe Girardi and his love for platoon matchups successfully used a duo of two opposite handed starting pitchers for games later in the season. When the manager lost confidence in Phil Hughes in the end of the 2013 season, he'd replace the right-hander with David Huff, a left-handed pitcher. This prevented teams from putting together lefty-heavy lineups to face a right-handed pitcher, or righty-heavy lineups to face a left-handed pitcher. Given the situation now, I'd imagine that Joe Girardi plans to use both Nuno and Phelps in a similar starting duo. He'll start the stretched out Nuno and then relieve him with Phelps for 3 or more innings.
The effects of losing Nova will also span the entire organization, and I wouldn't be surprised to see Manny Banuelos promoted to Scranton or Trenton quickly. Though he's been pitching in Tampa to give him regular starts in the warm weather, Banuelos could quickly see a promotion to see if he regained the stuff to pitch against higher levels of competition. Thus far, Banuelos has shown great command and strikeout stuff in Tampa, but he was also roughed up in his most recent outing.
The Yankees will undoubtedly miss Nova, but they at least have the depth of starting pitchers to replace the right-hander. Expect Girardi to start Nuno in the future, and relieve him with Phelps relatively early on in games. Once he's stretched out, Phelps may earn some starts against right-handed heavy lineups. I assume Girardi will use this Nuno and Phelps tandem until a better starting option presents itself in the system.