CINCINNATI -- Left-hander exited his start against the Reds with left groin tightness after throwing just one inning on Wednesday night at Great American Ball Park. 

Snell has dealt with a similar injury in the past, missing time in 2024 when he was with the Giants. 

Right-hander Blake Treinen began warming up in the top of the second inning and relieved Snell in the bottom half of the frame.

Snell threw 19 pitches while facing the minimum in the first inning, giving up a two-out single to Sal Stewart before he was erased on a pickoff-caught stealing. Snell threw eight four-seamers with an average velocity of 94.5 mph, down 1.5 mph from his season average.

This season, Snell has been on the injured list twice. He was sidelined by left shoulder fatigue to open the year and landed back on the IL after one start with loose bodies in his left elbow, which were surgically removed. He had been dominant since returning from the IL on Aug. 11, going 4-0 with a 1.04 ERA in six starts entering Wednesday.