Schedule could lead to another drop in polls for USC

USC travels north this weekend to play its Pacific 10 Conference opener at Washington State, but the Trojans might continue to head south in the Associated Press media poll even with the expected victory.

USC’s slide from No. 14 in the preseason to No. 20 this week came after the Trojans failed to sufficiently impress despite improving to 3-0 with a victory over Minnesota.

And the trend shows no sign of slowing down with USC playing the lowly Cougars, a three-touchdown underdog.

Washington State, under third-year Coach Paul Wulff, is 1-2. The Cougars’ lone victory was a 23-22 win over Montana State, a Football Bowl Subdivision school.

That victory came sandwiched between a season-opening 65-17 defeat by Oklahoma State and last week’s 35-21 loss to Southern Methodist.

USC Coach Lane Kiffin’s challenge will be convincing his players to take seriously a Washington State program that has not defeated the Trojans since 2002, when the Cougars won in overtime at Martin Stadium. The last time USC traveled to Pullman, in 2008, the Trojans won, 69-0.

Of course, USC has not overwhelmed anyone this season.

The Trojans’ offense staggered at Minnesota; quarterback Matt Barkley having passes intercepted for the first time in three games.

Tailback Allen Bradford gave the running game a boost with an assist from the offensive line.

“We love that,” senior left guard Butch Lewis said afterward. “Put it on us.”

For the Trojans to play what Barkley described as a “complete game” they must improve in all phases.

“Going to Pullman this week,” he said, “we’ll be looking to do that.”

Washington State offers the Trojans an opportunity to work out problems before a tougher October that includes games against Washington, 16th-ranked Stanford, California and fifth-ranked Oregon.

Washington State ranks last in the Pac-10 in scoring defense, giving up 40.7 points a game. The Cougars also are last in total defense (457 yards per game) and rushing offense (96.7 yards per game).

Quarterback Jeff Tuel has passed for 700 yards with five touchdowns and one interception. Against SMU, he was 18 for 33 for 284 yards and two touchdowns.

Freshman receiver Marquess Wilson is a deep threat who had more than 100 yards receiving against Oklahoma State and SMU. And running back James Montgomery, who nearly lost a leg after suffering a knee injury last season, rushed for 116 yards and a touchdown in 20 carries against Montana State.

Quick hits

Trojans defensive lineman Armond Armstead suffered a shoulder sprain against Minnesota and will probably be limited this week…. The Trojans resume practice Tuesday after having Monday off.

gary.klein@latimes.com