Iwakuma was shut down during his scheduled simulated game Saturday after feeling shoulder soreness, Greg Johns of MLB.com reports.

EDGE Analysis

Iwakuma stopped throwing just seven pitches into his simulated game, although the hope is that the setback isn't overly serious. Manager Scott Servais stated that early evaluations show tendinitis is likely the cause of Iwakuma's discomfort. The 37-year-old will cease throwing for the next few days before further evaluation and it's unclear when he could begin his minor-league rehab assignment.