Senzel (knee) had his option reversed by the Reds on Thursday, C. Trent Rosecrans of The Athletic reports.
Senzel was optioned to Triple-A Louisville on Sunday after he was reinstated from the 60-day injured list, but he was examined by several doctors this week who discovered fluid on his left knee. As a result, the 26-year-old will now revert to the big-league injured list, and he'll head to Arizona to continue his rehab process.