Senzel left Wednesday's game against the Brewers with an illness, C. Trent Rosecrans of The Athletic reports.
Senzel had missed three games last week with a hamstring injury, so his removal Wednesday initially sparked fears that the injury had returned. In that context, an illness is a clear positive for Senzel. The Reds have an off day Thursday, so there's a decent chance Senzel is healthy and ready to play Friday against the Rockies.