In five seasons at Oklahoma, Riley made four bowl games and won 55 games.
Christon and his lawyer are accusing USC of being racially insensitive.
The California native took an all-but-traditional path to becoming a Trojan.
The Trojans must win out to secure bowl eligibility, starting with the Cougars.
The Trojans made all of the usual mistakes in their loss at home.
UCLA running back Zach Charbonnet will be the main focus for USC.
The Trojans have multiple standouts ahead of the rivalry game.
The Trojans are looking to claim their fifth victory of the season.
The freshman quarter was named starter after an injury to junior quarterback Kedon Slovis.
Daily Trojan editors explain what they expect when USC faces UCLA.