4:19pm: The deal is now official, per announcements from both teams.
2:49pm: The Cubs are making a long-term addition to their bullpen, as they’re acquiring righty reliever Ryan Zeferjahn from the Angels. The Halos are getting catcher Moises Ballesteros and right-hander Mason McGwire in return. McGwire was not on the Cubs’ 40-man roster, so the deal is 40-man neutral for both clubs.
The 28-year-old Zeferjahn is having a steady season out of the Angels’ bullpen. In 51 2/3 innings, he has a 3.66 ERA, as well as a 33.5% strikeout rate that ranks in the 97th percentile in the majors, according to Statcast. ERA estimators are even more favorable to Zeferjahn, with xERA (2.93) and SIERA (3.37) putting him around half a run better than the 3.66 figure. Both his high-90s four-seamer (+2 Run Value) and his sweeper (+8) grade out as above average pitches and have helped Zeferjahn take a step forward in his third big league season.
Solid as those numbers are, Zeferjahn has been even better in the last two months. Dating back to June 1st, he’s fired off 26 innings with a 1.38 ERA and a staggering 41.9% strikeout rate. He’s still giving up his share of walks, running a 13.3% walk rate even during that dominant stretch. Nonetheless, Zeferjahn’s penchant for strikeouts and improvements with run prevention made him a valuable target for teams seeking relief help.
The Angels have mostly used Zeferjahn in low leverage spots this year, and he figures to take up the middle innings in the Cubs’ bullpen. The North Siders are currently working with a closer committee of Jacob Webb, Trent Thornton, and Caleb Thielbar. Webb has a 2.59 ERA and good strikeout and walk numbers in 48 2/3 innings. Thornton is outperforming his peripherals and only striking out 11.5% of opponents. Thielbar has an ERA just under 4.00 and an above-average strikeout rate, but he’s due for regression on a .247 BABIP. Zeferjahn could serve as a bridge to those three, striking hitters out in bunches while generally keeping the ball in the park.
On the Halos’ side, the deal is the latest in what’s becoming a rare deadline sell-off. Owner Arte Moreno has never been one to make sell-type moves, even in non-competitive seasons, but the situation appears to be different under interim general manager John Mozeliak. On Wednesday, they sent Logan O’Hoppe and Chase Silseth to the Rangers. Just today, they’ve traded Brent Suter to the Braves, Jo Adell to the Guardians, and Jose Soriano to the Blue Jays. Zeferjahn is now the sixth player the Angels have dealt off the big league roster in less than a week as they look to restock a depleted farm system.
In exchange for four-plus seasons of control over Zeferjahn, the Halos are picking up a highly-touted bat in Ballesteros and a low-level arm in McGwire. Ballesteros debuted for the Cubs last year and put up a 143 wRC+ in his first 66 plate appearances. He entered 2026 as a consensus Top-100 prospect in the sport, according to MLB.com.
Ballesteros has a .231/.303/.385 with a wRC+ of 91 in 175 plate appearances. This production is the balance between a red-hot first four weeks and then an ice-cold stretch once the calendar flipped to May. The Cubs opted to demote Ballesteros to Triple-A on June 18 and he hasn’t yet returned to the majors.
These ups and downs aren’t uncommon for such a young hitter, and they certainly don’t take away from Ballesteros’ prospect pedigree or his value to the Angels. He came up as a catcher but mostly served as a designated hitter with the Cubs. The Halos figure to use him the same way. They have veterans Tyler Heineman and Travis d’Arnaud behind the plate, along with Jorge Soler in the DH spot. Soler is a free agent after the season, so the team could look to trade him in the next hour as well, which would free up a regular spot for Ballesteros.
McGwire, the son of slugger Mark McGwire, was the Cubs’ eighth-round draft pick in 2022. He’s split 2026 between Low-A and High-A, tossing a combined 59 1/3 innings with a 3.64 ERA, 29.3% strikeout rate, and 9.8% walk rate. MLB.com had him at No. 18 on the Cubs’ Top 30 prospects before the trade. He’ll join the low levels of the Angels’ system and try to work his way to the upper minors in the next couple of years.
Zeferjahn is a pre-arbitration player and only making the $780K minimum. The remaining $231.9K will now be added to the Cubs’ payroll. Entering today, MLBTR’s new Payroll Tracker had Chicago at $236.8MM in cash payroll, as well as a $254MM luxury tax number. This deal will barely change those totals, as Ballesteros was earning near the minimum himself and effectively cancels out the new money for Zeferjahn. Their deal for Kevin Gausman, who’s earning $23MM this year, has been their biggest salary addition so far.
ESPN’s Jeff Passan was the first to report Zeferjahn going to the Cubs. Jeff Fletcher of the Orange County Register was first on Ballesteros and McGwire going to the Angels. Photos courtesy of Jon Endow, Darren Yamashita, Imagn Images
