There are obvious choices in Oregon, TCU and BYU, so let's exclude them from the discussion.
Looking at the schedule what game(s) worry you the most?
If I had to choose, it would be UNLV, CSU and -- I know I might be off on this -- Louisville.
I choose Louisville because they really are an unknown. Is Steve Kragthorpe that bad of a coach or did he just have an extremely rough start? I think the Cardinals have the talent to surprise this year and I'm just thankful the game is in Salt Lake. With that said, I'll concede I don't know much about Louisville, except they have to replace some key components of their offense.
San Jose State is another game that I think might prove difficult, since it's the second week of the season and on the road. Thankfully it's a late-start, which I think benefits Utah as opposed to an early morning West Coast game (think Boise State and SJSU back in 2004).
What games concern you the most?