In his junior year, Harrison helped Navasota to a 10–1 record and a berth to the UIL Region III-3A Division I final, which the Rattlers lost 28–34 in overtime to La Vega.
After redshirting his initial year at Texas A&M, Harrison served as the top backup on the offensive line for the Aggies.
Harrison got another start against Northwestern in the Meineke Car Care Bowl of Texas at left guard in place of the injured Brian Thomas.
Harrison injured his calf in the Chick-fil-A Bowl against Duke, and also underwent surgery to repair torn labrum in his right shoulder in January 2014.
[9] Harrison signed unto the practice roster of the Saskatchewan Roughriders of the Canadian Football League (CFL) in September 2017.