Barnett is slated to start Saturday's game against the Twins at Target Field, Jason Burke of Roundtable.io reports.
The Athletics called Barnett up from Triple-A Las Vegas on Wednesday, and after he wasn't needed in relief over the past three days, he'll end up slotting into the rotation as a replacement for the injured J.T. Ginn (finger). Barnett was a full-time member of the rotation at Las Vegas prior to his call-up, but all 13 of his appearances with the Athletics in 2026 have come out of the bullpen. As Burke notes, Barnett was limited to 38 pitches in his most recent start for Las Vegas on July 18, so the right-hander will likely be in store for a restricted workload in Saturday's outing.