One of the games within the game tonight, when Idaho and Washington State collide at Martin Stadium in Pullman, could be WSU's stout defensive line vs. Idaho's offensive line.

Idaho quarterbacks have been sacked 20 times in three games. That's eight more sacks than any other team in the nation has allowed.

Petrino said his line played better in last week's game vs. Northern Illinois, "they've just got to continue to improve."

Idaho is one of 16 FBS teams that have yet to throw an interception this season. Only three of the 16 have attempted more passes than the 87 pass attempts by the Vandals, with 84 of those coming from Chad Chalich.

He said the big reason for WSU's 10-7 win at USC was the Cougars' defense, in particular its defensive line.

"They're big and their physical, and 98 (Kalafitoni Pole, a 6-foot-1, 302-pound redshirt junior nose tackle) is a hard guy to block," Petrino said. "He just gets after people, throws 'em around. ... They're so big and physical, not too many people knock them off the ball. They pressured the quarterback quite a bit in that (USC) game with a three-man rush ... if you can get after the quarterback with a three-man rush, that's pretty tough."

WSU (2-1), in its second season under coach Mike Leach, had an excellent chance to beat Auburn in its opener, but too many turnovers doomed the Cougars in a 31-24 loss.

But their victory at USC suddenly has folks talking about a bowl game, something the Cougars haven't played in since 2003.

"They've done a real good job," said Petrino, 0-3 in his first season at Idaho. "They're probably a little ahead of schedule ... what they went through last year is what we're going through now. They're going to be a real good football team for years to come with coach Leach coaching them, and we've just got to go out there and compete and find a way to beat them."

And the key to stopping Leach's pass-happy, "Air Raid" offense?

"You've got to tackle the guys after the catch," Petrino said. "They're going to get completions. You have to be good tacklers, and you have to put pressure on the quarterback."

Idaho has given up at least 500 yards of offense in all three games, including 504 yards last week to Northern Illinois, which rallied for a 45-35 win by outscoring the Vandals 24-7 in the second half.

Idaho is fifth-worst in the country, giving up 554.3 yards per game so far. Only Miami of Ohio, Buffalo, New Mexico State and California are allowing more yards per game.

Idaho and Washington State have not met since 2007 - unless you count the off-field incident between players from the two programs last March.

Former Washington State wide receiver Mansel Simmons was found unconscious after a brawl in a Pullman church parking lot that involved Idaho wide receiver Roman Runner. No charges were filed in the case after prosecutors determined Runner was acting in self-defense, but Simmons' career was over after he suffered a severe concussion.

Leach and his players this week dismissed the idea that the brawl would have an impact on the game.

"I have no worries about that at all," Leach said.

Added quarterback Connor Halliday, "We're just worried about winning the game, that's the only thing on our mind."