He thereafter served as an assistant at the University of Maine (1951–1952), Eastern Michigan University (1953), Michigan (1954–1965) before joining the NFL with the Minnesota Vikings (1967–1970, 1978–1986), as the head coach of the National Football League (NFL)'s St. Louis Cardinals (1971–1972), and assistant coaching stints with the Detroit Lions (1973–1974), San Francisco 49ers (1975), and Seattle Seahawks (1976–1977).
During his first season with the team, he helped shape a group of linemen who became known as the "Purple People Eaters," including two future Hall of Famers in Carl Eller and rookie Alan Page.
Four years of success, including an appearance in Super Bowl IV, raised Hollway's profile and led to his hiring as head coach of the Cardinals on February 12, 1971.
[2] The Cardinals finished 4-9-1 in both of Hollway's seasons with the Cardinals, as the team suffered through numerous injuries and inconsistent play at quarterback, as Hollway shuffled between Jim Hart, Pete Beathard and Gary Cuozzo with little success, despite the presence of fleet wide receiver John Gilliam (who was traded to Minnesota in 1972) and future Pro Football Hall of Fame tight end Jackie Smith.
Following the retirement of Grant at the conclusion of the 1983 NFL season, Hollway was demoted by Les Steckel to quality control assistant, serving primarily as a personnel director and scout.