Rattler faced lofty expectations as a heavy preseason Heisman favorite, having posted big numbers during his first season, following in the footsteps of Heisman Trophy winners Kyler Murray and Baker Mayfield, as well as Heisman finalist Jalen Hurts, who he backed up as a true freshman.

However, Rattler was benched for the second consecutive year during Oklahoma's Red River Showdown against arch rival Texas, having re-entered the rivalry game to lead the Sooners back to victory in 2020.

This year, freshman Caleb Williams led Oklahoma to a 21-point comeback and kept the starting job for the remainder of the season.

Rattler ranked as the No. 1 pro-style quarterback, the No. 1 player from the state of Arizona and the No. 11 overall prospect for the 2019 national recruiting cycle, as well as the No. 238 overall prospect all-time, according to the 247Sports Composite rankings.

Rattler will now be eligible to compete immediately for his new team in adherence with recently revised NCAA transfer rules.

On Sunday (November 29) night, USC confirmed a reports that it had hired Riley as its next head football coach, which was initially reported by the Athletic's Bruce Feldman.

Riley is one of the biggest names in college football having led Oklahoma to four consecutive Big 12 championships during his first four seasons as the Sooners' head coach (2017-21) and three College Football Playoff appearances, as well as a 10-2 (7-2 Big 12) record in 2021.

The 38-year-old had previously served as the Sooners' offensive coordinator and quarterbacks coach in 2015 and 2016 under former Oklahoma head coach Bob Stoops, taking over as head coach after Stoops' retirement in 2017.

Stoops -- who had previously come out of retirement to coach the XFL's Dallas Renegades in 2020 -- will reportedly serve as Oklahoma's interim coach for its upcoming bowl game, Sports Illustrated reports.

The 61-year-old led Oklahoma to a national championship during his second season in Norman (2000), 10 Big 12 championships and eight Big 12 South Division titles, and 190 total wins, the most in program history.