The Mariners optioned Festa to Triple-A Tacoma on Sunday, Ryan Divish of The Seattle Times reports.
With Bryce Miller (finger) returning from the injured list to start Sunday, Festa will serve as the Mariners' roster casualty. The 30-year-old righty made two appearances during his latest major-league stint, throwing 2.1 scoreless frames while giving up one hit and striking out three.