The Philadelphia Phillies bullpen is getting a boost with the return of Orion Kerkering from the 15-day injured list. Kerkering recorded a 2.25 ERA and a 0.98 FIP in four minor league rehab appearances for Triple-A Lehigh Valley. In addition to that Kerkering had a 0.75 WHIP and a 5.00 K/BB rate. Kerkering returns from the injured list before Zack Wheeler who is also expected to return in April. The Phillies will have to make another 26-man roster decision when Wheeler is activated. Currently the Phillies have a full 40-man roster. That could change when Wheeler returns because of the corresponding move to this transaction to activate Kerkering.

Kyle Backhus has been optioned to Triple-A Lehigh Valley to make room for Kerkering on the 26-man roster. While Backhus had an excellent spring training he got off to a slow start in the regular season. Backhus has multiple minor league option years available which likely played a role in the decision as well. In four regular season outings Backhus has a 9.00 ERA and a 5.84 FIP along with a 1.67 WHIP and a 4.00 K/BB rate. Backhus and Tim Mayza were competing to be the third left-handed relief pitcher but both made the team due to the injury to Kerkering. Mayza has no minor league options. To add to that Mayza has a 0.00 ERA and a 1.32 FIP with a 0.29 WHIP as well as a 8.00 K/BB rate in five outings this year.

Sep 14, 2025; Minneapolis, Minnesota, USA; Arizona Diamondbacks pitcher Kyle Backhus (43) pitches to Minnesota Twins first base Kody Clemens (18) in the ninth inning at Target Field. Mandatory Credit: Matt Blewett-Imagn Images
Phillies Bullpen Return
Change In Balance

The Phillies now have three left-handed relief pitchers instead of four in their bullpen. Mayza is joined by José Alvarado and Tanner Banks. Furthermore the Phillies have five right-handed relief pitchers instead of four in their bullpen. Jonathan Bowlan and Zach Pop move into lower leverage roles with Kerkering returning. The Phillies bullpen will return to a more traditional split and that could be helpful for the team. It will allow for more favorable matchups because of there being less of a need for one of the left-handed relief pitchers to face multiple right-handed hitters in an inning. Regardless of what the corresponding move ended up being the Phillies bullpen improves by getting Kerkering back in the mix.

Role Adjustment For Kerkering Relative To Last Season

With Brad Keller signing a multi-year free agent deal this offseason the Phillies are giving Kerkering a lower leverage role. Keller is the primary right-handed setup man while Alvarado is the primary left-handed setup man. Kerkering took a step back in 2025 after a stellar 2024. In 2024 Kerkering had a 2.29 ERA and a 2.42 FIP with a 4.35 K/BB rate. For comparison in 2025 Kerkering recorded a 3.30 ERA and a 3.82 FIP with a 2.41 K/BB rate. Kerkering pitched five more high leverage innings in 2025 than he did in 2024. Kerkering had a 3.42 ERA and a 1.25 WHIP with 116 batters faced in the eighth inning of games last season compared to a 0.84 ERA and a 0.94 WHIP with 43 batters faced in the eighth inning of games in 2024.

Credit Image: © PI via ZUMA Press Wire