Hultzen is dealing with soreness in his throwing shoulder and will be shut down for a few days, MLB.com's Greg Johns reports.
Hultzen suffered what was termed "a little setback," but this is concerning given that his 2015 season came to a close due to a left shoulder injury. It's not clear when he will be ready to pitch next, but expect the Mariners to release an update on his status at some point in the next few days.