 Christensen played professional football in the National Football League for eight years for the Portsmouth Spartans (1931–1933) and the Detroit Lions (1934–1938).He started in 74 of 95 games that he played.He was selected as a first-team All-NFL player in 1931, 1933, 1934 and 1936, and a second-team All-NFL player in 1932 and 1935.