Greinke was placed on the 15-day injured list with a right flexor strain Monday.
Greinke was evaluated for a flexor injury following Sunday's start against Minnesota, and he'll land on the injured list after being diagnosed with a strain. The right-hander will be forced to miss at least a couple of turns through the rotation, but a timetable for his return isn't yet clear. The Royals haven't yet indicated who will step in as a starter during Greinke's absence.