The Yankees have a reputation for being able to churn out effective young relievers over and over again, but the 2015 Yankees weren't so successful in that regard. Of course, they still had one of the best bullpens in baseball, thanks to former in-house products like Dellin Betances and Adam Warren, but most of their shutdown bullpen came from free agency (Andrew Miller) or shrewd trades (Chasen Shreve, Justin Wilson). When it came to new players coming up from the farm system, the Yankees got burned.
To be fair, for most of the season, the Yankees got incredible results from Miller, Betances, Wilson, Shreve, and Warren, so they didn't exactly NEED any kind of help. However, once Shreve fell apart in the second half and Warren was pushed back into the rotation, someone out of the multitude of call-ups needed to step up, but no one did. Guys like Nick Goody and Nick Rumbelow, who are expected to be important backend bullpen guys didn't amount to much in their first taste of the big leagues. Goody utterly dominated the upper minors this year before getting pushed up to the majors, however he allowed four runs on six hits and three walks in just 5.2 innings, likely taking him out of the running to pick up some of the slack, as far as Joe Girardi was concerned. Rumbelow is expected to be another late-inning reliever, but he pitched to a mediocre 4.27 ERA in 52.2 innings at Triple-A and couldn't do much more in the majors with a 4.02 ERA in 15.2 innings.
The Yankees were expecting big things from Bryan Mitchell, but 2015 proved to be pretty ugly for him. He actually pitched to a 3.86 ERA in his first 21 innings this season, but after he was hit in the face by a comebacker on August 17, Mitchell was a 12.46-ERA of a disaster in his remaining 8.2 innings over 10 games. Another reliever, Caleb Cotham–who was not even expected to ever reach the majors–made a bad first impression as a 27-year-old rookie. After being converted into a reliever this season, Cotham demolished the upper levels of the system before making it into 9.2 innings with the Yankees. Unfortunately, he was trounced when he allowed seven earned runs on 14 hits and four home runs (!) in just 12 games. It was a nice surprise to see him get a chance, but it shouldn't be shocking if he's no longer on the 40-man roster by spring training.
Then there was the injury bug. Jacob Lindgren made his much-anticipated major league debut and with all our expectations came crushing disappointment as the lefty was knocked around in his short stint with the team. Soon after his demotion, it was announced that he would need surgery to remove a bone spur from his elbow and he missed the rest of the season. I guess the silver lining there is that once he's healthy, he should still offer the Yankees an excellent option out of the bullpen. Diego Moreno, who the Yankees got in exchange for A.J. Burnett, gave us his heart and soul when he pitched 5.1 shutout innings in relief against the Texas Rangers on July 28 and then promptly went down with an elbow injury only a few days later. Who even knows what happened to him, but it's more than likely that they had to amputate.
The Yankees did get a few decent performances in the first half of the season, at least. Chasen Shreve was an integral part of the bullpen for almost the entire year, pitching to a 1.89 ERA and keeping opposing hitters to a .180/.282/.322 batting line in 52.1 innings through the month of August. By that point he was completely out of gas and allowed a 13.50 ERA in the month of September, ultimately leading to a shallow bullpen and his expulsion from the playoff roster. He should be an important member of the bullpen next year, but the end of this season was pretty brutal. Branden Pinder provided some misleading success as he pitched to a 2.93 ERA, but a 4.72 FIP on the year, likely due to his 5.43 FIP and 6.35 BB/9 in the second half of the season. It's hard to tell which is the real Pinder, but he should at least get another chance next year. Finally, there was James Pazos, who actually proved to be somewhat impressive in September and even earned a spot on the playoff roster. He allowed only three hits and walked three in five innings across 11 games as Girardi used him for mostly matchup purposes, but as we saw in the beginning of the season, several effective lefties are good to have.
It's incredibly likely that some of these pitchers won't be a part of the 2016 team. Whether by injury, transaction, or ineffectiveness, the Yankees will still need more depth to get them through the season. Expect next year's rookie crop to include at least some of Tyler Webb, Brady Lail, Johnny Barbato, Alex Smith, Cale Coshow, Eric Ruth, and Rookie Davis, but we still should see more of Goody, Rumbelow, Lindgren, and the other disappointments, who can hopefully look a little better over a longer sample size. Things didn't go so well for relief prospects in 2015, but there's no cause for concern. It sucked, it hurt, but now we have a fresh start, more options, and a better chance come next year.