As impressive as the Arizona football team's schedule may be this season, the Wildcats' toughest test of the year still lies ahead.

Arizona's slate has been littered with Top 25 opponents - like No. 3 Louisiana State, No. 8 Washington State, No. 10 TCU and No. 11 Purdue - but none has had more to lose when facing the two-win Wildcats than No. 2 Southern California.

USC comes into Tucson this weekend ranked second in both major polls as well as the Bowl Championship Series list, and the Trojans expect to be playing in the Sugar Bowl for the national championship if they continue winning.

"This is certainly one of the top teams in the country. They have great talent, they utilize that talent, they play hard, and they execute," said Arizona interim head coach Mike Hankwitz. "They are not ranked second in the BCS for nothing."

USC comes into Saturday's contest as the most talented team in the Pacific 10 Conference. The Trojans have a defense that has been dubbed the "Wild Bunch II" - after USC's 1969 defensive front - and an offense that leads the Pac-10 in scoring.

The Trojans are also among the nation's best in punting (first), rush defense (third), turnover margin (fifth), scoring (sixth) and pass efficiency (ninth).

To add to USC's advantages, the Trojans come into the game off a bye week and have had two weeks to prepare for the Wildcats.

"They are fast - probably the fastest team we've played all year," sophomore linebacker Marcus Smith said. "Plus, they have talent all over the field."

The USC defense is led by a strong group up front. Its defensive line has four key veterans returning from a group that finished sixth in the nation last year against the run.

The front four is made up of senior Omar Nazl and junior Kenech Udeze at defensive end as well as junior defensive tackles Mike Patterson and Shaun Cody.

"They are excellent," Hankwitz said. "When you have big guys that are athletic and can run, it just adds another dimension to you, and they have those kind of guys. They are going to be a tremendous challenge for our offense."

Besides having one of the top defenses in the country, the Trojans also bring one of the country's most potent offenses to Arizona Stadium.

USC has used a running back by committee approach in its ground game this season. The Trojans' top three backs have more than 1,400 rushing yards combined. Freshmen LenDale White and Reggie Bush, along with sophomore Hershel Dennis, have all taken a substantial number of carries this season. All pose a threat to the Wildcats.

A large reason for the success of the offense has been the play of its offensive line. The Trojans front five have given up a Pac-10 low 11 sacks in 2003.

"They are big - real big. They are all 300 (pounds)-plus," Smith said.

That same line has made things easy for sophomore quarterback Matt Leinart, who's taken over without a hitch after the departure of 2002 Heisman Trophy winner Carson Palmer to the NFL. Leinart's 2,366 yards and 24 touchdowns - with just seven interceptions - have given the Trojans one of the most balanced attacks in the country.