Born in Edmond, Oklahoma, Mornhinweg played high school football in San Jose, California.
[1] He led the Oak Grove Eagles to a Central Coast Section championship in 1978 with a 52–7 rout of defending champion St. Francis of Mountain View in the title game at Spartan Stadium.
[2] Following the 1978 championship season as a junior, Mornhinweg was the 1979 Northern California Player of Year as a senior, but the Eagles fell 32–29 in the semifinals to Salinas.
During his junior season in 1982, Mornhinweg led the Griz to its first Big Sky Conference championship in a dozen years.
While a collegiate assistant coach, Mornhinweg became the starting quarterback for the Denver Dynamite in the Arena Football League in 1987.
[9] Mornhinweg's decision making was met with astonishment and mockery from the press and ESPN anchor Chris Berman.
Coach Andy Reid gave Mornhinweg the play-calling responsibilities after the Eagles' disastrous loss to the Indianapolis Colts, 45–21.
The wins included a three consecutive December divisional road games, all with a back-up quarterback, Jeff Garcia.
Instead of continuing to coach under Reid in Kansas City, Mornhinweg took an offensive coordinator position with the New York Jets in 2013.
Mornhinweg has coached five different quarterbacks who earned Pro Bowl selections: Brett Favre, Steve Young, Jeff Garcia, Donovan McNabb, and Michael Vick.