Donaldson (shoulder) exited Saturday's game against the Nationals due to dehydration, Gregor Chisholm of MLB.com reports.
Donaldson has been battling a shoulder issue throughout camp, but the early exit was apparently unrelated to his shoulder. It's an unusual situation and a potential yellow flag for the veteran third baseman, but it's entirely possible that this was a one-off case of dehydration and that the team didn't feel the need to push things in a Grapefruit League contest.