Cubs upgrade bullpen with Ryan Zeferjahn, give up Moises Ballesteros in trade with Angels

A day after addressing the top of their starting rotation and making a trade-deadline splash by landing veteran righty Kevin Gausman, the Cubs upgraded their relief corps, bringing in 28-year-old right-hander Ryan Zeferjahn in a deal with the Angels.

It cost them one of their top young players, with slugger Moises Ballesteros going the other way in the trade.

Zeferjahn has been very effective this season, already logging 51⅔ relief innings and posting a 3.66 ERA. He’s been even better over the last couple months, with a microscopic 1.38 ERA in 24 appearances since June 1.

Zeferjahn is in his third big league season, his ERA down more than a full point from last season, when he made 62 relief appearances.

Zeferjahn was almost exclusively a late-inning option for the Angels. Since the start of May, he pitched earlier than the seventh inning only twice.

For much of the season, injuries have forced the Cubs to piece together their bullpen, and their pitching staff in general. Injuries to expected contributors such as righties Phil Maton and Hunter Harvey and closer Daniel Palencia have forced unexpected arms into high-leverage roles, with righties Jacob Webb and Trent Thornton, as well as lefty Ryan Rolison, stepping into late-inning jobs.

Zeferjahn, who finished 17 games for the Angels this season, figures to join that late-inning group.

After hitting nearly .300 and reaching base at nearly a .400 clip in 2025, Ballesteros started this season with the expectation of playing a key, if not everyday, role for the Cubs. But his numbers weren’t nearly as good in limited playing time this time around, hitting .231 and posting just a .303 on-base percentage before being sent to Triple-A Iowa in mid-June to receive more regular at-bats.

In 32 games with the I-Cubs this season, Ballesteros hit just .235.

Also going the other way in the trade is pitching prospect Mason McGwire, son of legendary slugger Mark McGwire, who was rated as the No. 18 prospect in the Cubs’ organization.

The Cubs also made a move for a minor league starter, acquiring lefty Braxton Garrett from the Marlins in exchange for a pair of top-30 prospects. Garrett was immediately sent to Triple-A Iowa as a depth piece.