But he soon departed for a new expansion team when he was appointed the first-ever general manager of the Seattle Mariners when they entered the American League in 1977. Although the under-capitalized Mariners struggled during Gorman's four seasons in Seattle—they posted a 246–400 (.381) record from 1977–1980 with two last-place finishes in the AL West—he obtained early Mariner standout Ruppert Jones in the 1976 Major League Baseball expansion draft (from his old Royals' organization) and drafted centerfielder Dave Henderson with his first-ever No. 1 choice in the June 1977 Major League Baseball draft.