Playing career College career Freshman and redshirt freshman seasons In 2004, Harrell redshirted his first season at Texas Tech. The following season, he served as the backup quarterback behind another Texas Tech record setter, Cody Hodges, who led college football in passing yards in 2005. Sophomore season Harrell started in every game of the 2006 season, beating out classmate Chris Todd. Harrell got the Raiders off to a quick start with wins over Southern Methodist University, The University of Texas at El Paso, Southeastern Louisiana University and conference rival the Texas A&M Aggies. The lone Red Raider loss was to Texas Christian University, 12–3 in the third game of the season. Despite the 4–1 start, Harrell was benched halfway through the next game due to poor play after the Raiders fell behind the Missouri Tigers 24–0, and Todd was inserted for two series. Harrell came back into the game and got the Raiders within 3 points before the half but struggled in the second half as Tech lost 38–21. The next week against a winless Colorado team that Tech was heavily favored to beat, Harrell once again was benched in favor of Todd for a 4 interception game resulting in a 30–6 loss. However, Harrell rebounded to throw for 6 touchdowns against the Iowa State Cyclones and then threw for 519 yards and 3 touchdowns against the Texas Longhorns in a narrow 35–31 loss. The Raiders finished the season with a 55–21 win against the Baylor Bears, a 34–24 loss to the Oklahoma Sooners, and a 30–24 win against the Oklahoma State Cowboys. Texas Tech finished the regular season 7–5 (4–4 in the Big 12) and received an invitation to the 2006 Insight Bowl. The 7–5 Red Raiders faced off against the 6–6 Minnesota Golden Gophers at the 2006 Insight Bowl in Tempe, Arizona. Texas Tech struggled on both offense and defense during first 3 quarters of the Insight Bowl. The Minnesota Golden Gophers outscored Tech 38–7 through the end of the 3rd quarter. The Red Raiders, sparked by a 43-yard touchdown from Harrell to Joel Filani, went on to outscore the Gophers 31–0 through the end of regulation sending the game into overtime. On the final drive, Harrell drove the Red Raider offense almost 70 yards in less than a minute to set up the game-tying field goal by Alex Trlica. Following a Minnesota field goal, Tech scored a