Darnold is five weeks shy of his 21st birthday, which is difficult to believe considering he likely would have been the No. 1 overall pick in the 2017 NFL Draft had he been eligible under NCAA rule.
Darnold completed 64.9 percent of his passes for 7,229 yards with 57 touchdowns and 22 interceptions in his 27-game career. He broke the USC single-season passing yardage record as a sophomore.
The youngest starting quarterback when the 2017 season opened was Jared Goff (22) of the Rams. He was the first overall pick in the 2016 NFL Draft.