Santillan (back) will report to Triple-A Louisville on Tuesday to begin a rehab assignment, C. Trent Rosecrans of The Athletic reports.

EDGE Analysis

Santillan was placed on the 15-day injured list with his back injury on Opening Day and didn't get a chance to pitch in the Cactus League. The right-hander is expected to work in a relief role once back with the Reds, and barring a setback that should take place sometime in the middle of April.