The No. 6 Cardinal is one of just eight remaining undefeated teams in the country and boasts a 36 point average margin of victory. It has run up at least 40 points in every game but one. It has held opponents to 10 points or fewer three times. It beat Arizona in Tucson by 27 points. A week ago, it trounced then-No. 25 Washington 65-21.Stopper · Senior linebacker Chris Galippo and the USC defense will try to slow down Stanford’s vaunted run game, which ranks 17th nationally. – Mannat Saini | Daily TrojanStanford’s (7-0, 5-0) win against USC last year kicked off its current 15-game winning streak, and the last nine of those wins have come by more than 25 points.“It’s just the mentality that they have,” Kiffin said. “A lot of people thought they would be lost with all the staff changes, but they didn’t get lost. And then the personnel changing. But it doesn’t matter who’s in [the game]. They just play downhill and physical. They’re relentless.”The loss of coach Jim Harbaugh — who led the program from a 1-11 record in 2006 to a BCS bowl and a top-five ranking last year — to the NFL was expected to be too much for Stanford to overcome.Quarterback Andrew Luck is widely regarded as the best in college football and Stanford’s best since John Elway was in Palo Alto.“I’ve heard people describe him as ‘perfect,’” senior linebacker Chris Galippo said. “A guy like that, we know he’s their leader. He’s probably the toughest guy on their team. We know what type of competitor he is and it’s up to us to stop him.”Luck was the runner-up in the in Heisman Trophy vote last season and looks even better this year. Luck has completed 71.8 percent of his passes this season, throwing for 20 touchdowns to just three interceptions and a 180.0 quarterback rating — good for fifth in the nation.“We’ve got to be able to stop the run so he can’t sit back there all day with play actions,” Kiffin said. “We’re really going to have to be on our coverage and make him make tough throws.”—Stanford, however, isn’t all about Luck. Despite all the Heisman hype, the Cardinal is a run-first team. Stanford ranks 17th in the country in rushing offense with nearly 220 yards per game and second in the nation in points scored at 48.6 points per game.“We’re going have to play great on both sides of the ball up front,” Kiffin said. “There’s no way to beat this team while playing finesse, especially on defense. We’re going to have our hands full.”The Cardinal often plays with three tight ends in its formation, a versatility few teams enjoy. Tight end Coby Fleener is the Cardinal’s leading receiver with 384 yards and seven touchdowns. His 22.6 yards per catch are good for fourth in the country and best among tight ends.The diversity of Stanford’s offense puts increased pressure on the Trojan defense, a unit that has played very well as a whole during the last two games.“We’ve been playing a lot better on defense of late,” Galippo said. “We’ve got to keep up that consistency.”Galippo, in last year’s loss to the Cardinal, committed an unfortunate late-hit penalty that gave the Cardinal 15 extra yards in its final game-winning drive.“I think about it all the time,” Galippo said of the penalty. “It was obviously pretty crucial and probably cost us the game. It was a learning experience for me to just be more aware.”—Redshirt sophomore cornerback Torin Harris once again did not practice. Kiffin expanded on the redshirt sophomore cornerback’s injury, saying it’s a nerve problem in his shoulder.“They test him every day,” Kiffin said. “There’s nothing he can do [right now].”Freshman running back George Farmer also did not practice after being carted off the field with a leg injury Tuesday. Freshman kicker Andre Heidari and sophomore receiver Robert Woods were both limited. Woods wore a non-contact jersey.