Rex competed in the Plano-Plano East rivalry all four years of his high school career, playing a pivotal role in each of the rivalry games he competed in. Specifically, in 2007 and 2008, Burkhead accounted for a total of six touchdowns between the two final years of his time as a Wildcat playing the Panthers of Plano East. In 2OO7, Rex touched the ball a total of 32 times, sealing the victory with a six-yard rushing touchdown carrying the Wildcats to a victory that turned the momentum of the rivalry in Plano's favor. Following his career at Plano, Rex went on to be a four-year letterman at the University of Nebraska, competing for two Conference Championships during his tenure there. Rex was drafted by the Cincinnati Bengals, spending 4 years there before signing with his current team, the New England Patriots. Rex has been heavily involved in philanthropic work in his community, widely known for the creation of his non-profit organization known as the Team Jack Foundation, which focuses on research and development for pediatric brain cancer.