He has been an offensive coordinator for the NCAA's Utah Utes, Houston Cougars, and Florida Gators and the NFL's Philadelphia Eagles.
[1] After graduating early, Johnson was a two-star recruit coming out of high school, not being ranked among the top quarterback prospects of his class.
As a true freshman in 2004, Johnson saw action in ten games as back-up to Heisman Trophy finalist Alex Smith.
[1] In 2005, Johnson took over as starting quarterback, where he remained for the first ten games until a season-ending knee injury against New Mexico on November 12.
[1] After undergoing surgery on December 1, 2005, to correct his knee injury, Johnson redshirted his third year in order to convalesce during the 2006 season.
They went on to compile wins against Air Force, Oregon State (who defeated USC the previous week), and twelfth-ranked TCU, a team that only had one other loss in the season (against future BCS Championship Game participant second-ranked Oklahoma.)
[7] After going undrafted in the 2009 NFL draft, he was invited to the Green Bay Packers' rookie mini-camp, along with Tulsa quarterback David Johnson.
[9] He was not signed by an NFL team, but the Winnipeg Blue Bombers of the Canadian Football League were reportedly interested in him.
Mullen had offered him a scholarship to sign with Utah during Urban Meyer's tenure as the Utes' head coach.
Johnson was promoted to offensive coordinator in 2023, replacing Shane Steichen who departed to become head coach of the Indianapolis Colts.