Friday's move cleared roster space for Ryan Rowland-Smith to be recalled from Triple-A Tacoma. Rowland-Smith started Friday night against Cleveland, his first for Seattle since April.
Corcoran was 2-0 with a 6.16 ERA in 16 games this season. He had a six-week stint on the disabled list with a strained neck.
Seattle has 10 days to trade or release Corcoran, or send him outright to the minor leagues.
Also Friday, infielder Josh Wilson was outrighted to Triple-A Tacoma. He was designated for assignment July 21.