I've been preparing through all of this as if I was the starter.
Just not so soon.
Heaps entered the game after starter Riley Nelson suffered a broken rib and a lung injury in the first quarter and led the Cougars to five scoring drives in six possessions in an easy 42-7 victory over the Vandals at LaVell Edwards Stadium.
Given another chance to show what he could do after losing the starting job to Nelson earlier in the season, Heaps completed 15-of-20 passes for 185 yards, two touchdowns and one interception.
"I've been preparing through all of this as if I was the starter," Heaps said. "It was unfortunate that Riley went down. We're praying that he'll be OK and that he'll return quickly. I'm going to go out there and do what I can to help our team."
Nelson, who was taken to the hospital, sustained a broken rib and a "small pneumothorax" (a collapsed lung), according to team doctors. Nelson was expected to remain hospitalized overnight.
"When that happened we were all sad for Riley," said running back Michael Alisa, who added that he and other teammates were planning on visiting Nelson in the hospital later that night.
Coach Bronco Mendenhall said Nelson suffered the injury while throwing a 32-yard touchdown pass to Cody Hoffman in the first quarter. The referees said it was "a clean hit," Mendenhall said.
"He took a solid shot on the touchdown throw," he added. "Jake came in and managed the game well. He moved the team well, made a lot of good decisions, and got a lot of quality work."
The Cougar offense rolled on the ground and through the air against the porous Vandal defense. BYU had 505 yards of total offense — 243 yards rushing and 262 yards passing.
"I was pretty pleased by the way we did things," Heaps said. "From the very beginning, we were moving the ball and pretty much did whatever we wanted to, which is a great sign."
Wide receiver Cody Hoffman caught six passes for 114 yards while Alisa rushed 10 times for 99 yards and a touchdown.
BYU's defense limited Idaho to 241 yards of total offense and one touchdown.
With the win, BYU improved to 7-3 on the season. Idaho dropped to 2-8.
The Cougars moved the ball almost at will most of the night. They failed to score on their first drive after Justin Sorensen's 35-yard field goal attempt drilled the left upright.
But on its second series, BYU drove 64 yards in one minute as it scored on that 32-yard touchdown pass from Nelson to Hoffman. Nelson completed 4-of-7 passes for 56 yards on the night.
When the Cougars got the ball back, Heaps took the field and led a nine-play, 78-yard drive that took 5:17 off the clock, capped by a one-yard TD run by Bryan Kariya as BYU seized a 14-0 advantage.
The Cougars scored again on a 13-play, 75-yard drive in 5:49 that resulted in a one-yard touchdown run by Kariya to make it 21-0 midway through the second quarter.
BYU's defense stopped Idaho in the waning moments of the quarter and Mendenhall called a timeout to give the offense a shot at another score with 1:03 remaining in the half. Taking over at the Cougar 30-yard line, Heaps promptly marched the Cougars downfield, highlighted by a 22-yard pass to J.D. Falslev. One play later, Heaps threw a 21-yard TD pass to Hoffman with 13 seconds remaining in the half, staking BYU to a 28-0 lead at intermission.
At that point, the Cougars had 298 yards of total offense, compared to 63 for Idaho. The Vandals had minus-2 yards passing.
BYU wasted little time building on its lead, scoring on three plays in 48 seconds, including a 38-yard touchdown run by Alisa — Cougars 35, Vandals 0.
Heaps led another drive deep into Idaho territory but ended with an interception when he overthrew fullback Zed Mendenhall.
Idaho finally got on the scoreboard on an 82-yard touchdown run by Princeton McCarty with 3:56 left in the third quarter.
At that point, junior James Lark came into, and finished, the game.
BYU halted another potential Vandal touchdown with four minutes left thanks to an interception by Spencer Hadley in the end zone, which he returned to the Cougar 48-yard line.
BYU hosts New Mexico State next Saturday (8:15 p.m., MT, ESPNU).