Last season, a Holiday Bowl bid was on the line for the winner of the USC-Arizona game. Tonight, the Trojans are playing mostly for pride while the Wildcats try to bounce back from a loss to Stanford and improve their bowl standing. Here are the game's key issues:
First, the secondary
USC is ranked last in the Pacific 10 Conference in pass defense, Arizona fourth.
But don't be fooled: Both secondaries are struggling and will be targeted.
Arizona gave up 293 yards passing last week in a 42-17 loss against Stanford. Coach Mike Stoops pulled highly regarded junior cornerback Trevin Wade during the game and replaced him with freshman Shaquille Richardson.
The Wildcats will try to contain Trojans receivers Ronald Johnson and Robert Woods, who appears to be back to full speed after being limited last week because of a bone bruise and illness.
USC's defense could stick with the 4-2-5 nickel alignment it used against Arizona State. Cornerbacks Shareece Wright, Torin Harris and Nickell Robey and safeties T.J. McDonald and probably first-time starter Marshall Jones will try to slow down Wildcats receiver Juron Criner, the Pac-10 leader with 6.4 receptions and 98.2 receiving yards per game.
USC quarterback Matt Barkley has had consecutive two-interception performances against Oregon and Arizona State. He is third in the Pac-10 and 23rd nationally in passing efficiency, with 24 touchdowns and eight interceptions.
Arizona's Nick Foles sat out two games because of a dislocated kneecap before returning against Stanford. Foles is fourth in the Pac-10 in passing efficiency, having thrown for 10 touchdowns and six interceptions in seven games.
Backup quarterback Matt Scott, who led the Wildcats to victories over Washington and UCLA, has an injured wrist.
Making a run
Freshman tailback Dillon Baxter made his first start for USC last week against Arizona State and did nothing that would cause him to lose the job.
But junior Marc Tyler came off the bench to rush for 119 yards before suffering a sprained ankle. If Tyler is sufficiently recovered, he could start.
Meantime, senior Allen Bradford is trying to work back into a more prominent role after a toe injury and ball-security issues dropped him in the rotation.
Arizona's Keola Antolin, generously listed at 5 feet 8, averages five yards a carry and has rushed for seven touchdowns. Nic Grigsby has scored eight touchdowns but is nursing an ankle injury.
Bring the pressure
Arizona's Ricky Elmore leads the Pac-10 with seven sacks and fellow end Brooks Reed is tied for third with five. D'Aundre Reed, a former standout at Moreno Valley Rancho Verde High, also rotates in at end and has two sacks.
The Wildcats are tied for sixth nationally with 27 sacks.
USC was able to get pressure on Arizona State quarterback Steven Threet, sacking him four times, but Arizona runs a faster-paced short passing game. Trojans tackle DaJohn Harris has a team-best 3 1/2 sacks and end Wes Horton and Nick Perry have three each.
Arizona gives up an average of nearly 2 1/2 sacks a game.
USC's Joe Houston kicked the winning field goal against Arizona State, but the senior missed two attempts earlier in the game and is six for 12 this season. Jacob Harfman has averaged 42.5 yards a punt.
USC's Johnson is second in the Pac-10 in punt returns, averaging 17.7 yards, and Woods is sixth in kickoff returns, averaging 25.4.
Arizona kicker Alex Zendejas has made 10 of 12 field-goal attempts, including five of six from beyond 40 yards. Keenyn Crier is averaging 41.2 yards a punt.
Travis Cobb is third in the Pac-10 in kickoff returns, averaging 27.4 yards, and William Wright is seventh in punt returns, averaging 6.1 yards.