What the Mariners can look to expect from Paul Sewald in 2023

Division Series - Seattle Mariners v Houston Astros - Game One
Division Series - Seattle Mariners v Houston Astros - Game One / Carmen Mandato/GettyImages

The Seattle Mariners have made a living from taking struggling and seemingly failed relievers from other teams and getting them on low-risk deals. A recent example of a successful endeavor has been Paul Sewald, who has become a high-leverage reliever in the Mariners’ bullpen from 2021–22. 

Sewald spent his first four years in MLB with the New York Mets, going 1–14 in 125 appearances. His 5.50 ERA over those 147.1 innings led to a 73 ERA+, meaning he was well below average in his time in Queens. His stuff was also not as dominant, as his 3.1 BB/9 and 9.2 K/9 are worse than in Seattle. 

In just two seasons with the Mariners, he has pitched in a nearly equivalent amount of games, 127. He is 15–7, along with 31 saves. He also boasts a 2.87 ERA over 128.2 innings with a 2.9 BB/9 and 12.3 K/9. His strikeouts per walk, going from 2.96 with the Mets to 4.29 with the Mariners, has been a major key to success for the righty. 

The change in his Baseball Savant page is probably the most impressive part of his transition from someone not cut out to play in the MLB to a near All-Star level reliever. 

In 2018, he filled with white and blue circles, but in 2022, those circles were overwhelmingly bright red. His 2018 to 2022 percentiles were: Average Exit Velocity (53rd to 91st), xBA (49th to 93rd), Whiff % (27th to 93rd), xERA (56th to 92nd), Fastball Spin (64th to 95th), K % (54th to 86th) and finally xSLG (52nd to 87th). 

After his strong 2021 season, it was tough to predict which Sewald we would get in 2022, but now that he has shown that his first year in Seattle was not a fluke season, expectations are high for him to continue being a force in the backend of the rotation. 

Over the past two seasons, he has sat at around 60 innings, so my prediction will keep in line with that. I think that with the surrounding parts in the bullpen, he may even pitch in slightly lower-leverage situations, which will certainly help his stats for next season. However, I think most fans expect Sewald to be the closer in 2023, or at least a set-up high-leverage reliever. 

2023 Prediction: 63 games, 67.0 innings, 2.88 ERA, 0.899 WHIP, 12.2 SO/9, 2.8 BB/9