There offense cannot catch up. So they don't want BYU to get possessions to allow them to score and force Utah to rely on their offense.
Whit will come with multiple dive options, jumbo packages, and jet sweeps. They will come with so many new run plays. They also will use short screen passes and quick throws behind the line as a wrinkle to the run game. They will huddle and run clock.

BYU needs to run zone blitzes to keep Isaac off key and to keep people in the box for the run, They need to keep rotation on DL because run game is very grueling. Utah doesn't rotate OL much so BYU can wear them down with fresh DL pressure.