The Mariners optioned left-hander Zac Curtis to Double-A Arkansas with their corresponding move.
Cishek, who began last season as Seattle's closer until Edwin Diaz took over in early August, went 4-6 with a 2.81 ERA and 25 saves in 2016. He was originally placed on the DL on March 31 as he was recovering from the surgery and then went 1-0 with a 3.00 ERA, seven strikeouts and four walks in seven combined rehab appearances, including two starts, with Arkansas and Triple-A Tacoma.
Among Mariners relievers in 2016, Cishek led the club in appearances (62), innings pitched (64) and opponents' batting average (.190) while ranking second in strikeouts (76). His .190 opponents' average against ranked 10th best among American League relievers last season. He went on the disabled list with a left hip labrum tear last Aug. 4.
Doug Miller is a reporter for MLB.com. Follow him on Twitter @DougMillerMLB. This story was not subject to the approval of Major League Baseball or its clubs.