The team said Thursday it would not seek a replacement for Sullivan and offered no other details.
Sullivan, who played one season with the Coyotes, was hired by Arizona in 2014 under previous general manager John Chayka. He was promoted to assistant GM in 2017 and served as interim GM last year when Chayka left the team.
Sullivan also served as general manager of the Tucson Roadrunners, Arizona’s AHL affiliate.
He played 16 NHL seasons with Toronto, Chicago, Nashville, Pittsburgh, Arizona and two stints with New Jersey before retiring in 2014.