Since joining the Chicago Cubs at the trade deadline, right-handed reliever Ryan Zeferjahn has faced a challenging adjustment period on the mound. The 28-year-old, acquired from the Los Angeles Angels, has posted a 5.79 ERA with a 74 ERA+ in 9 1/3 innings across 10 appearances, allowing seven runs (six earned) and issuing four walks while striking out nine batters. This marks a notable decline from his performance with the Angels, where he recorded a 3.66 ERA, a 112 ERA+, and 75 strikeouts in 51 2/3 innings, including a stretch with a striking 1.13 ERA and 44.8% strikeout rate prior to the trade.

Zeferjahn acknowledged that while there is nothing alarming about his recent outings, he has struggled to find the consistent sharpness and command that characterized his earlier success. “Everything’s still there, and it’s just kind of a click off,” he said. He explained that changes in mechanics and the adjustment to a new team have contributed to some of the difficulties, noting his fastball has been solid but not always in the strike zone. His recent outing, however, showed promise as he struck out two of four batters faced over 1 1/3 innings, generating eight pitches that were either called strikes or swings and misses—his second-best mark since joining the Cubs.

Cubs manager Craig Counsell emphasized the inevitability of ups and downs for relievers and expressed confidence in Zeferjahn’s potential. “Ryan, he’s been a little scattered since he’s been here. I think he’s really close. I think we can get him there,” Counsell said. He underlined the importance of giving pitchers continued opportunities to rebound from tough stretches.

Zeferjahn’s success depends largely on the mechanics of his lower body and improved pitch location, particularly with his fastball. He is focusing on refining his delivery and not just “throwing them” as he did before. Over the course of the season, fatigue and multiple challenging stretches have tested him, but he remains optimistic about regaining form and contributing to the team’s success.

The right-hander’s arsenal includes a four-pitch mix: a sweeper, four-seam fastball, sinker, and slider, with an occasional curveball. Pitching coach Tommy Hottovy noted that Zeferjahn’s two strongest pitches—the sweeper and four-seamer—are most effective when complemented by regular use of his sinker and slider, adding variety to keep hitters off balance. “His strengths are the sweeper and fastball, but still finding a way to mix the other pitches to keep hitters honest,” Hottovy said. He also highlighted the importance of catchers Carson Kelly and Miguel Amaya understanding Zeferjahn’s pitching approach, which relies on the full mix rather than defaulting to just two pitches.

The Cubs are working to simplify Zeferjahn’s mechanics by focusing on fundamentals such as his foot placement and body alignment on the mound. Considering the pitcher’s 6-foot-5 frame, they aim to help him maintain linearity in his delivery and strength in his east-west movement, which enhances his pitch spin. Catch play and routine repetitions are being used as opportunities to reinforce these adjustments.

Zeferjahn is hopeful that settling into his new role and refining his execution will allow him to fulfill the expectations that accompanied his midseason acquisition.