Barriera exited Saturday's start for Low-A Dunedin with an apparent left arm injury, Keegan Matheson of MLB.com reports.
Barriera threw a pitch, got the ball back, walked behind the mound and fired the ball into the ground in frustration before walking off the field with the trainer. It's not clear exactly what he's dealing with, but it's worth noting the left-hander dealt with an elbow issue for a big chunk of last season.