He served as head football coach at Rice University from 1967 from 1970, compiling a record of 12–27–1.

He moved to Southern Methodist University in 1954, where he worked for two seasons as backfield coach with Woody Woodard.

In 1956, Jess Neely hired Hagan as his backfield coach at Rice University.

He assisted Neely for 11 seasons before succeeding him as head coach after the 1966 campaign.

This biographical article relating to a college football coach first appointed in the 1960s is a stub.