That changes fast on both sides of the ball. Arizona's defense didn't allow a rushing yard to speak of against Northern Arizona, finishing with -7 yards on the ground, but BYU's run game with LJ Martin and its offensive line is a different weight class entirely. BYU, meanwhile, is breaking in reinforcements in the secondary — starting safety Raider Damuni is expected to miss a chunk of his senior season with a leg injury, and cornerbacks Jonathan Kabeya and Kevin Doe are both out, thinning a group that already has to replace last year's answers.
None of that shows up in a season-opening blowout score, which is exactly the problem with judging either team off Week 1. Arizona hasn't beaten BYU since the two programs revived this old WAC-era rivalry, including last season's double-overtime loss in Tucson, and Saturday is the first time either team's real ceiling gets tested.
LJ Martin, the reigning Big 12 Offensive Player of the Year, barely got worked in the opener — 7 carries for 54 yards — and BYU has more than enough depth pieces to lean on if the coaching staff wants to establish him early against an Arizona front that's about to see real resistance for the first time. Provo's forecast calls for cloud cover and temperatures near 90 degrees for the early-afternoon kickoff, the kind of conditions that can wear on a traveling defense by the fourth quarter.
How Arizona's defense handles a Bachmeier offense that can beat you with his arm or his legs, and how BYU's thinned-out back end holds up against Fifita, are the two threads that actually decide this one — everything else from the season openers is background noise.