LOS ANGELES - Observations from warmups before the Arizona Wildcatsโ game against USC on Saturday night at the L.A. Memorial Coliseum (6:30 p.m., Pac-12 Networks):
* Arizona senior right guard Cody Creason didn't make the trip. Creason, an iron man for the UA offensive line, hurt his lower leg/foot in the second half vs. Washington last week.
*ย With Creason out, hereโs what the Wildcatsโ starting line will look like, from left to right: Donovan Laie, Paiton Fears, Josh McCauley, Bryson Cain, Edgar Burrola. Guard Robert Congel, who started the first five games, is dressed but worked with the second team.
*ย It appears that senior defensive back Jace Whittaker will shift from corner to safety for this matchup against USCโs Air Raid-style offense. Whittaker previously started at safety vs. Texas Tech.
*ย With Whittaker shifting to the inside, Christian Roland-Wallace will start at corner opposite Lorenzo Burns. The odd man out appears to be Christian Young. Tristan Cooper came out of the lineup against Texas Tech, but heโs been playing too well lately to spend the game on the sideline.
*ย Tailbacks Gary Brightwell and Bam Smith, who both sat out last week, are in uniform and participated in warmups.
*ย On the USC side, defensive end Christian Rector (ankle) is out, as is linebacker Palaie Gaoteote IV. Cornerback Isaac Taylor-Stuart, among several banged-up Trojans DBs, is dressed and is expected to play but wonโt start.
Be sure to check Tucson.com and the Wildcaster app for updates during and after the game. You can also follow me on Twitter at @michaeljlev.