Herz (elbow) was diagnosed Monday with a left flexor strain, Kyle Williams of TheBanner.com reports.
It's a significant setback for Herz, who has been working his way back from April 2025 Tommy John surgery. The left-hander posted a 1.17 ERA, 0.52 WHIP and 11:0 K:BB in 7.2 innings covering his first three rehab starts, potentially setting him up for activation around the All-Star break. After suffering the flexor strain, however, Herz will be out indefinitely.