Stanford leads the nation in rushing defense, but maintaining that level of play could be difficult without star linebacker Shayne Skov.
The sixth-ranked Cardinal will be back in action Saturday night for the first time since losing Skov as they host UCLA in search of their 12th straight victory.
Skov is out for the season with a knee injury suffered in the second quarter of a 37-10 victory at Arizona on Sept. 17. Wildcats receiver Juron Criner was tackled and knocked into Skov's leg on the play.
The junior led Stanford (3-0, 1-0 Pac-12) with 84 tackles last season to go with 7 1/2 sacks and was considered a potential high NFL draft pick.
"He's the emotional leader of the defense. You can't replace that," safety Michael Thomas said.
The loss of Skov is the first major challenge in front of first-year coach David Shaw, whose defense has allowed an average of 36.0 rushing yards through three games.
"It's a big loss for our football team, but we have great leadership on defense from players such as Michael Thomas, Delano Howell and Chase Thomas," Shaw said. "We've also recruited very well recently and now it is time for guys to step up."
Stanford should be tested Saturday since UCLA (2-2, 1-0) ranks second in the conference with 214.0 yards per game on the ground. The Bruins are the only school with two rushers in the Pac-12's top 10, with Johnathan Franklin averaging 75.8 yards and Derrick Coleman 74.8.
Any defensive shortcomings can be partially alleviated by Heisman Trophy favorite Andrew Luck and an offense that has produced an average of 481.3 yards. Luck has eight touchdowns, one interception and 786 yards passing.
The Cardinal lost five straight meetings to the Bruins before Luck guided them to victories in his first two seasons. He has not needed to throw for big yardage in either contest, completing 11 of 24 passes for 151 yards and two scores in last year's 35-0 rout.
Despite that lopsided score, Franklin rushed for 73 yards on 11 carries for UCLA and has a 5.2 career yards-per-carry average in two games against the Cardinal.
UCLA coach Rick Neuheisel said that Luck is "unquestionably the best quarterback in the country."
Neuheisel was encouraged by his team's 27-19 road win at Oregon State in its Pac-12 opener last Saturday. Coleman rushed for 100 yards, and three other Bruins scored touchdowns on the ground.
"I know there are people who will say it wasn't this and wasn't that, but ultimately when you come away with a victory, you just feel like more is possible," Neuheisel added. "Our guys are energized. They're looking forward to this week of practice. There will be a bounce in their step. It doesn't mean any extra points on Saturday, but you can feel good things are on the horizon."
Neuheisel worked alongside Shaw in 2005 with the Baltimore Ravens, and recruited against Shaw's father, Willie, from 1989-91 while Neuheisel was a young UCLA assistant and Willie Shaw was Stanford's defensive coordinator.
"I battled his father years ago when I first broke into this business, and now I'm battling his son," Neuheisel said. "David has earned this opportunity, and I'm certainly pulling for him ... but not this week."
The Bruins have split their last eight games against top 10 opponents, including a stunning upset of then-No. 7 Texas on the road last year.
A hidden matchup to watch in this game could take place in special teams. Stanford's Drew Terrell is third in the Pac-12 in punt return average at 15.7 yards, while UCLA is yielding a conference-worst 19.2 yards per punt return.
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UCLA's pistol offense and rushing attack will be the biggest challenge to Stanford's run-stopping superiority so far this season. The Bruins average 214 yards per game on the ground. The Cardinal lead the nation, allowing just 36 yards per game. And now they have to do it without their best run-stopper, Shayne Skov. Something has got to give.