In 1955, Spavital joined the Oklahoma State coaching staff under coach Cliff Speegle. In 1968 he joined the Saskatchewan Roughriders as an assistant. In 1970 he was hired by the Winnipeg Blue Bombers as head coach. In four seasons as Bombers head coach, he had a 23–39–2 record and two playoff appearances.
In 1974, Spavital was hired as head coach of the Chicago Fire of the World Football League. The team finished 7–13 and folded after the season. In 1975 he joined the New York Jets, coaching the offensive backfield. The following season, he again coached the offensive backfield coach for San Francisco 49ers coach Monte Clark.
Spavital left the Roughriders after the season to join the Michigan Panthers of the United States Football League (USFL). In the league's first year, the Panthers won the USFL championship, defeating the Philadelphia Stars title title game. On September 9, 1983 he resigned his post as Panthers GM. In 1989 Spavital was hired by Bill and Hubie Byrne to help put together a new professional football league to begin play in the spring or summer of 1990. Spavital was the director of football operations for the Professional Spring Football League (PSFL) for two years before plans for the league were abandoned.