Many of the prospects that change hands at the MLB trade deadline will be anonymous to casual fans. That will not be the case with one deal between the Chicago Cubs and Los Angeles Angels.
The Cubs reached an agreement to acquire relief pitcher Ryan Zeferjahn from the Angels on Monday. In return, the Angels are receiving two prospects, one of whom is Mason McGwire, the son of slugger Mark McGwire.
To get reliever Ryan Zeferjahn from the Angels at the deadline, the Cubs are planning to give up Moisés Ballesteros and pitching prospect Mason McGwire (Mark’s son) in the trade, per source confirming reporting from @JeffFletcherOCR.
— Patrick Mooney (@PJ_Mooney) August 3, 2026
This is a homecoming of sorts for the younger McGwire, who was born and raised in Orange County. The Cubs had drafted him out of Capistrano Valley High School in Mission Viejo, Ca. in the eighth round of the 2022 MLB Draft.
The comparisons between Mason and his father end pretty quickly, as Mason is a pitcher. He has shown himself to be a pretty good one as well, though he has hit a bit of a rough spot since being promoted to high-A South Bend with a 4.91 ERA.
Zeferjahn, the main piece of the deal, has a 3.66 ERA and 75 strikeouts in 51.2 innings with the Angels this season. Los Angeles clearly thinks McGwire has a future in the game if they wanted him in return for a fairly valuable reliever.
