Chicago bolsters its bullpen with a high-velocity strikeout specialist under long-term control, sacrificing a former top hitting prospect to secure a late-inning bridge for the future.
The Chicago Cubs aren’t done adding at the trade deadline.
After trading for Kevin Gausman and Braxton Garrett over the past 18 hours, the Cubs have finally addressed their bullpen by trading for Los Angeles Angels reliever Ryan Zeferjahn. Chicago is sending Moises Ballesteros and Mason McGwire back to Los Angeles as part of the deal.
Full Trade Details:
Cubs Receive: Ryan Zeferjahn
Angels Receive: Moises Ballesteros, Mason McGwire (No. 18)
The Cubs needed some bullpen help at the deadline, and got just that with the addition of Zeferjahn. The hard-throwing right-hander has a 3.66 ERA, 1.200 WHIP, and 75 strikeouts across 51 ⅔ innings pitched this season. He also has a 1.38 ERA and a 41.9% strikeout rate in his last 24 appearances dating back to June 1.
There are two things to love most about Zeferjahn.
The first is that he is under team control for another 4 ½ seasons. Zeferjahn will not be a free agent until after the 2030 season. The Cubs are getting a high-upside bullpen arm for the foreseeable future.
The second is that he brings elite strikeout potential to the backend of Chicago’s bullpen. He struck out 73 batters in 57 innings last year and has 75 strikeouts in 51 ⅔ innings this season. Zeferjahn's swing-and-miss stuff is his strong suit. That will firmly put him in key high-leverage spots the rest of this year and the rest of his Cubs tenure.
Zeferjahn is exactly the type of bullpen arm the North Siders needed. He is the perfect setup man for closer Daniel Palencia. The former Angels reliever is having a breakout campaign, and his numbers under the hood should get the Cubs excited.
Zeferjahn currently ranks in the 89th percentile in expected ERA (2.95), 100th percentile in expected batting average against (.161), 87th percentile in average fastball velocity (97 mph), 96th percentile in whiff rate (34.6%), 97th percentile in strikeout rate (33.6%), and 80th percentile in barrel rate (5.6%).
The walks can be a problem for him at times. The right-hander posted a 13.3% walk rate last year and has a 13.9% walk rate this year. However, he gets out of most of that damage with his elite swing-and-miss stuff.
The cost for an up-and-coming reliever with 4 ½ years of team control was never going to be cheap. Unfortunately, that meant parting ways with former top prospect Ballesteros.
Ballesteros got off to a hot start with the Cubs this season. He batted .387 with five home runs, five doubles, and 16 RBI in his first 25 games. But struggles in May/June forced Chicago to option the young hitter to Triple-A. Those struggles then continued at Triple-A, as the 22-year-old batted .235 with two home runs and 23 RBI across 32 games at Iowa before being traded.
McGwire also heads to Los Angeles as part of this deal. McGwire was the Cubs’ No. 18 prospect and was one of the biggest risers in the farm system this year. He has a 3.64 ERA and 72 strikeouts across 59 ⅓ innings at Single-A and High-A in 2026.
The Cubs no doubt paid a hefty price to acquire Zeferjahn. However, he’s a controllable reliever who throws hard and has elite swing-and-miss stuff.
