Who the Athletics Might Promote in September 

September is drawing near, and while many associate September with the beginning of the school year and the start of fall (and the Halloween season), in baseball, September means expanded rosters and rookie debuts. The Athletics, a team already loaded with rookies, has its sights set on the 2026 playoffs. September is set aside for prospects to audition for a roster spot next season. To simplify things for this final month of the season, and as a guide for some of the possible debuts, I’ve broken down some of the most likely prospects. 

 The first prospect mentioned is RHP Braden Nett. The A’s number 6 prospect acquired in the Mason Miller trade with the Padres is 23 years old and currently a starter, though he seems to project as a reliever; at that point, he could lose either his curveball or his cutter and become primarily a fastball-slider-changeup pitcher. Paring down his pitch mix could transform Nett into a quality MLB caliber arm. 

Another potential September callup is fellow top ten prospect Henry Bolte. The 2022 second-round draft pick is in the midst of a breakout offensive season in AAA Las Vegas. The speed and power combination in the outfield immediately brings to mind Christian Yelich, and with CF seemingly locked down by fellow rookie Denzel Clarke, Bolte could find a home in one of the corner outfield spots, where he could shine at the plate. 

A third prospect, again a trade deadline acquisition, but this time from the Royals in the 2024 Lucas Erceg swap, Mason Barnett, was a 2023 drafting pick and has shot through the minors. The 24-year-old RHP holds a 6.13 ERA through 25 games this season. Despite this, Barnett has struck out over 9 batters/9 IP, and has allowed only 17 HR over those 25 appearances, indicating that a fresh start may wipe away Barnett’s base runner issues. 

The fourth and final postseason debut of this preview is Daniel Susac. The former first-round draft pick is a solid defensive catcher with a good arm and above-average tools at the plate. The 6’4” 24-year-old has steadily improved at every level of the minors, and a good backup/eventual heir to Shea Langeliers behind the plate is a need for a playoff-hungry young core.