In 1996, Treliving co-founded the Western Professional Hockey League (WPHL), and he performed an integral role in the 2001 merger of the Central Hockey League (CHL) and WPHL. In 2003, he became assistant general manager of the Phoenix Coyotes under Don Maloney, while also serving as the GM for the team's American Hockey League affiliate, the San Antonio Rampage.[1] He held both positions until April 28, 2014, when the Calgary Flames hired Treliving to be the new general manager of the Flames.[2] On April 17, 2023, five days after the conclusion of the Flames' 2022–23 season, and with his contract expiring, the team and Treliving mutually agreed to part ways.[3] On May 31, 2023, Treliving was hired as the new general manager of the Toronto Maple Leafs.[4]