Kolek (oblique) threw three innings and 49 pitches Thursday during a simulated game at extended spring training, MLB.com reports.
Kolek is in the process of building back up after suffering a Grade 1 left oblique strain in late February and missing the remainder of the Cactus League. The 28-year-old remains in Arizona but could soon report to an affiliate to begin what will likely be an extended minor-league rehab assignment. Kolek isn't projected to return from the Royals' injured list until late April or early May.