A native of Grand Rapids, Michigan, Stanley signed with the Detroit Tigers organization in 1960. After four years in the Tigers' minor league organization, he made his major league debut in September 1964. He remained with the Tigers for 15 years from 1964 to 1978. He appeared in 1,516 games with the Tigers, 1,175 of them as a center fielder. He won four American League Gold Glove Awards (1968, 1969, 1970, and 1973) and ranked among baseball's all-time leaders in career fielding percentage by an outfielder.