Yankees' relievers were excellent for much of the 2017 season as suspected, however there were some significant downturns for the relief crew as well.
Let's review the performance of the Yankees' 2017 relievers with innings pitched used to sort through the players.
Green went from fifth starter hopeful to long-man/fireman reliever with spectacular results. Green, who wants to start, may have sealed his fate with the club because of how dominant he was as a reliever. Out of the bullpen, he struck out 100 batters in 67 innings with a 1.69 ERA.
Green became the go-to reliever when things got rough in the middle innings because he could shut rallies down and then continue on for more work.
Betances suffered through one of his worst seasons in recent years, despite a strong start and a successful turn as the closer. He finished the season with a 2.87 ERA, 1.21 WHIP and a stellar 15.1 strikeout rate.
However, Betances was WILD. His 6.6 walk rate and 11 batters hit by pitch were career highs. Betances became so unreliable in September that he received mop up duty and was virtually nonexistent in the playoffs.
Warren is the unsung performer in the bullpen. He is not like the others in that his strikeout rate does not jump off the page, but he got the job done in 2017, and could have been a bigger contributor had he not endured an injury late in the summer. Warren pitched to a 2.35 ERA, 0.87 WHIP and held opponents to a .173 batting average in 57 1 /3 innings. Like Green, he wanted to be a starter, but it seems that ship has sailed with the Yankees, who are quite content with the steady production he provides in relief.
Chapman had an up and down season, one which actually saw the $86 million closer demoted while he worked through a lengthy period of ineffectiveness. He also spent a month on the disabled list, making his first season (3.22 ERA, 1.13 WHIP, 12.3 K/9, 22 SV, 4 BS) in the five-year contract one to file far back in the memory banks.
Fortunately, Chapman finished the season strong and was dominant in the playoffs (8 IP, 1 ER, 2 BB, 16 K).
Shreve is a serviceable reliever (45 1/3 IP, 3.77 ERA, 1.32 WHIP and 11.5 K/9), especially for the type of action is was often asked to handle. He is not especially flashy and was increasingly wild this season (5.0 BB/9). His ability to stick around through the season was likely attributed his left-handedness.
Robertson was exactly what the Yankees needed at precisely the right time when he returned to New York. He came into the fold and basically pitched at any moment that Girardi needed big outs. Further, Robertson was used for lengthier outings as the season wore on and became an integral piece to the Yankees regular season finish and postseason run.
With the Yankees, Robertson pitched to a 1.03 ERA, 0.74 WHIP with 51 strikeouts in 35 innings. In the postseason, Robertson sparkled in the beginning (8 IP, 1 ER) but began to run out of gas in the ALCS (5 IP, 5 ER).
Kahnle was the least known players coming to the Yankees in the White Sox trade, but he slotted in nicely in the backend bullpen scheme for the Yankees. In 26 2/3 innings with the Yankees, Kahnle recorded a 2.70 ERA, 1.31 WHIP and 36 strikeouts. He had some exceptional moments in the postseason (11 1/3 IP, 3 ER, 10 K), eventually taking over innings that would have been typically handled by Betances.