 From 1955 to 1956 Milliken divided his playing time between Fort Worth and Montreal.Following his playing retirement, he returned to the majors as a bullpen and pitching coach with the St. Louis Cardinals (1965–70, 1976).He is given credit in the "SABR" biography of Jim Willoughby for straightening out his delivery in 1975, while serving as a pitching instructor when Willoughby was with the Tulsa Oilers.