He served as both the head football coach and athletic director of the University of South Carolina (1975–1981).

In 1979 and 1980, Carlen led the Gamecocks to consecutive 8–4 campaigns with appearances in the Hall of Fame Classic and Gator Bowl.

In July 2008, four years before his death, Carlen was inducted into the Texas Tech Athletics Hall of Honor.

[1] Coach Carlen was actively involved in the Fellowship of Christian Athletes (FCA) during his entire post-coaching life.

[3] A memorial service was scheduled for Friday, July 27, at 4 p.m. at the Trenholm Road United Methodist Church in Columbia, South Carolina.