Hayes exited Friday's game against the Blue Jays in the top of the sixth inning due to left shoulder discomfort, Alex Stumpf of DKPittsburghSports.com reports.
Hayes went 0-for-2 with a strikeout to begin Friday's game, but he appeared to sustain a shoulder injury on a diving attempt in the field and was replaced defensively to begin the sixth inning. The 25-year-old is considered day-to-day for now.