Cubs acquire reliever Ryan Zeferjahn from Angels for Moisés Ballesteros

The Cubs made another move to shore up their pitching staff with hard-throwing right-hander Ryan Zeferjahn from the Angels.

Zeferjahn, 28, was a third-round pick of the Red Sox and was traded to the Angels in 2024 as part of a deal for right-hander Luis Garcia. He made his major league debut that August and has been a fixture of the Halos major league bullpen ever since.

Zeferjahn is primarily a fastball/sweeper pitcher with a hard four-seamer that averages 97 miles per hour. But his out pitch is an 85 mph sweeper that has 14.8 inches of break on it.

This season, Zeferjahn has made 45 appearances and has a 3.66 ERA and four saves in six chances. He’s one of the pitchers who has served as the Angels closer and his four saves is tied for the team lead with the now-Rockies arm Jordan Romero. He strikes out a ton of batters with 75 in 51.2 innings, but that big-breaking sweeper means he’s walked a way-too-many 32. That control is what is keeping Zeferjahn from being a truly elite reliever as opposing hitter manage to hit just .161 off of him.

Zeferjahn isn’t even arbitration eligible until after the 2027 season and is under team control through the 2030 year. So he can be a factor in the Cubs bullpen for a while, either as a closer or a setup man.

We now have the return on this deal and it’s a big one.

Ballesteros, or Mo Baller as he’s known, was expected to be a Cubs DH and third catcher this year. But after he got off to a terrific start in April, the league adjusted to him and he ended up back in Triple-A Iowa. Ballesteros, 22, struggled badly in Iowa. He’s still dogged by the issue of where he can play on the diamond as he’s a poor defensive catcher and at 5’8″, he’s not ideal as a first baseman. But up until this May, he’s always been able to hit.

Mason McGwire, the son of Mark, is going home to Orange County. McGwire was a eighth-round pick of the Cubs in 2022 and for his first three years in the Cubs system, he looked to be a mess as he couldn’t find the plate. But after missing all of 2025 with an injury, McGwire came back this year with improved control. McGwire combines a mid-90s fastball with a big curve that’s a real weapon if he can get it over the plate. He’s a starter for now, but he’s most likely a reliever if he makes the majors. MLB Pipeline ranked McGwire as the Cubs’ 18th-best prospect and Baseball America had him at 20. I also put him at 18 in my mid-season update.