Utah's got a week to get some things worked out with the new offense while not revealing too much. Starters should be healthy and well rested. Little travel.
BYU will have played 2 games already, one physically demanding with travel mixed in against an exciting opponent the week before. I'd imagine BYU might be a bit beat up after that LSU game.
Utah will be coming off a Thursday night tuneup at home and BYU is a short "road trip", so I expect Utah to be tuned up, healthy and well rested. I'm supposing motivation and focus will not be a problem.