The Mariners optioned Hancock to Triple-A Tacoma on Friday.
The right-hander was called up for a spot start Thursday against the White Sox, but he won't stick on the big-league roster despite allowing just two runs across seven innings. Hancock has a 4.79 ERA, 1.28 WHIP and 24:13 K:BB over 41.1 major-league innings this season, and he should be in the mix for a promotion whenever Seattle needs rotation help.