Seattle placed Munoz on the 15-day injured list Sunday with a right deltoid strain, Ryan Divish of The Seattle Times reports.
Mariners manager Scott Servais said that Munoz hasn't been bouncing back well from his most recent relief appearance Friday and needs a short break. The right-hander felt something in his shoulder and underwent imaging, and now he'll be shut down for a few days before being re-evaluated. While Munoz is out, Paul Sewald should see the majority of save chances for Seattle, but Matt Brash could also get looks in the late innings.