Austin Cassidy was a standout performer for Coach Mark King at Lincoln Southwest High School, and is projected as a defensive back for the Huskers. He was a first-team Super State pick by the Lincoln Journal Star and a second-team All-Nebraska selection by the Omaha World-Herald. Cassidy compiled a 14-1 record as the Silverhawks' starting quarterback, including a perfect regular season in 2006. The 6-1, 205-pound Cassidy rushed for 1,507 yards as a senior, averaging a Class A best 8.3 yards per carry, with eight runs of 40 or more yards. A captain on the football team, Cassidy was also a track standout. He qualified for the state meet in the pole vault, the 110- and 300-meter hurdles in his junior and senior seasons, and was the Class A gold medalist in the pole vault as a junior. Cassidy also attracted recruiting interest from Northwestern, Air Force, Buffalo, Princeton, Cornell, South Dakota, Northern Colorado and UNO.
He is the son of NU Associate Athletic Director for Football Operations Tim Cassidy.