Former walk-on Baker Mayfield has beaten out the Oklahoma quarterback who , Trevor Knight, Greg Whittington Jersey and will start in the Sept. 5 season opener against Akron for the Sooners. | Sooners coach Bob Stoops .The transfer from Texas Tech, who was also initially a walk-on with the Red , competed for the job in the preseason with Knight and sophomore Cody Thomas. Stoops said Monday that Knight Will Barton Jersey will serve as Mayfield's backup while Thomas will be the No. 3 QB. Dikembe Mutombo Jersey At Texas Tech in 2013, Mayfield threw for 2,315 yards in just eight games as a freshman.Earlier this year, Mayfield also scored some points with his new teammates .Mayfield's rise also marks a fall for the career of Knight, who looked like the future of the position for the Sooners in a 45-31 win over Alabama in the Sugar Bowl following the 2013 season (348 yards, four touchdown pa ses). Last year, however, R.J. Hampton Jersey Knight struggled at times, mi sed three games with a , and returned to deliver his worst performance of the season in a 40-6 Ru sell Carmelo Anthony Jersey Athletic Bowl lo s to Clemson (17 of 37, three interceptions).*Follow Chase Goodbread on Twitter *