Herrin left Saturday's game against the Pirates in the eighth inning of due to a left arm injury, Chris Assenheimer of the Elyria Chronicle-Telegram reports.
Herrin was hit in the arm by a liner from Oneil Cruz, and the 27-year-old reliever was replaced by Eli Morgan shortly thereafter. Across his 19 outings since the All-Star break, Herrin has a 3.63 ERA and 1.04 WHIP across 17.1 innings.