A Grantsville native and Snow College veteran, Harrison was the backup quarterback through much of the early season. Entering Saturday's game, he had appeared in five contests and completed 23 of 46 passes for 263 yards and a pair of touchdowns.
Garretson, a true freshman from Arizona, has yet to make his first college start.
Tight end misses game
Senior tight end D.J. Tialavea was not dressed for Saturday night's game, missing his first start of the season.
Tialavea had been a key role player on the team, especially as a blocker for the offense. The 6-foot-4, 260-pound tight end had also caught 17 passes for 93 yards and three touchdowns. He was added to the list of offensive starters who were not suited up for Boise State, including Keeton, Kyle Whimpey and Joe Hill.
Keegan Andersen started in Tialavea's place, the junior's fourth start this year.
Third straight sellout
For the third consecutive game, Utah State sold out Romney Stadium. The Aggies had never before had three sellouts in one year, and never three in a row. The athletics department had been anticipating a sellout, reporting that 700 tickets were available as of Wednesday morning.
Utah State has also sold its most season tickets ever this year: 10,015.