The Cardinals promoted Hjerpe from High-A Peoria to Double-A Springfield on Tuesday.
Hjerpe earned the promotion after collecting a 3.35 ERA and 56:20 K:BB over 37.2 innings covering 11 starts. The Cardinals have been careful with the left-hander's workload after he had elbow surgery in 2023, as Hjerpe hasn't gone more than four innings or thrown more than 67 pitches in a start this season. It's possible the reins on the 23-year-old's restrictions will be loosened a bit now as he moves up a level.