Last year, Red Sox relief pitchers ranked 9th in baseball with a 4.9 fWAR. Midseason acquisition Brad Ziegler was the star of the bunch, posting a 1.52 ERA in 29.2 innings for Boston. Ziegler has since departed to the Marlins, leaving the Red Sox without a true bullpen ace. Instead of paying top dollar to replace him, the Sox are fortunate enough to have an elite in-house option in Joe Kelly.
Since being acquired from the Cardinals, Kelly hasn’t exactly lived up to expectations. Back in July of 2014, the Red Sox acquired Kelly along with 1B Allen Craig in exchange for John Lackey. To this point the trade has looked like a complete and total loss for the Red Sox. Lackey had a career year in 2015 while Craig and Kelly were both demoted to AAA after very poor performances in Boston. Kelly had always been a starting pitcher with very good “stuff,” but he wasn’t the kind of pitcher that could face batters 2-3 times in a game.
Kelly got off to another rough start at the major leagues in 2016. He lasted only 22.1 innings in 6 games started, posting an ERA of 8.46 while allowing an OPS of 1.001. Unsurprisingly, Kelly was once again demoted to AAA. Upon his return he was used strictly out of the bullpen. As it turns out, Red Sox ownership owes manager John Farrell a big “thank you” for making that decision.
As a reliever Joe Kelly was absolutely lights-out. Though he only pitched 17.2 innings out of the bullpen last year, he showed much promise in that role. He held batters to a 1.02 ERA, with an OPS of .558. He struck out more than a batter per inning, surrendering only one home run out of the bullpen. Even Kelly’s FIP (2.35) and xFIP (2.56), which have always been higher than his ERA, were supportive of his work.
“It really isn’t hard to make that switch. You just have to be mentally tough and mentally prepared for any situation that is given to you and take pride in whatever you have to do that day.” – Joe Kelly (Courtesy of Viva El Birdos)
While Kelly’s success out of the pen may sound like a new concept, he’s actually been an effective reliever before. In 70.1 career relief innings Kelly has compiled 70 strikeouts with a 2.69 ERA, stranding opposing runners on base at a 86.5% clip. He’s only pitched one full season’s workload as a reliever, but it’s more promising than his future as a starter.
With the departure of Ziegler and Koji Uehara, the Red Sox have a hole to fill in the pen. Tyler Thornburg was acquired from the Brewers in December, but the Sox could benefit from having a reliable bullpen staple. Kelly’s been unable to perform consistently since arriving in Boston, and moving to the pen may be his best shot at finding success again. He’s pitched in a very small sample size to look at, but if Kelly can replicate that level of production across 60+ relief innings, the Red Sox have themselves an ace in the bullpen.