 Prothro also decried the Pac-8 rule that only allowed the conference champion to go to a bowl game; he witnessed many lower ranked inferior teams from the Big Eight, Southeastern and Southwest conferences (often ones he defeated during the season) go to bowl games while his Bruins stayed home.After George Allen was fired by the Los Angeles Rams, Prothro accepted that job, leaving the Bruins after six seasons and a 41–18–3 record.Prothro was inducted into the College Football Hall of Fame as a coach in 1991.

Pepper Rodgers came to UCLA from Kansas after the departure of Prothro.