The senior missed the majority of last season due to a knee injury, but according to Kelly he hasn't "shown any ill-effects", leading them in tackles per game.
"They really thrive off of him," he said.
Skov is one of five senior members on the front seven that makes up the "best defense" Kelly has seen thus far.
"They've got some kids that we've played a lot of football against, so we understand them. [Ben] Gardner, [Terrence] Stephens, then [Trent] Murphy, Chase Thomas on the edge and Shane Skov in the middle, are guys that have been around a long time," he said of the experienced unit.
According to Kelly, the Cardinal try to set their linemen up in one-on-one situations, where they usually best their opponent. Offensive guard Nick Cody says this week will give the Duck offensive line an opportunity to prove themselves against one of the nation's best units.
"I think the biggest thing is that we're going to be challenged this week to come out and play physical," he said. "We're a physical team too. That's what it's going to take."
Stanford averages 4.3 per game sacks this season, the Oregon offense allows just 1.4. While blitz recognition and releasing the ball quickly will be effective ways for the Ducks to beat the Cardinal, the Ducks' tempo might be their biggest shield.
"They won't be able to cheat as easily if we just keep running the ball and line up as fast we can," Cody said. "Hopefully we can get the ball off before we even see the blitz."
Doing so won't be an easy task, as Helfrich says he's "yet to see them outside their comfort zone this season".
If the front-seven is the biggest strength for the Cardinal, it might be the Ducks' biggest point of concern. The defensive line entered the season as perhaps the defense's strongest unit, but a rash of injuries left just freshmen and walk-ons available for the Ducks in last week's win over California.
An inexperienced front could pose problems against a Stanford team that often lines up tight, with extra tight ends and even linemen in order to provide extra blockers in the run game. Even with the loss of first-round draft pick David DeCastro and second-round pick Jonathan Martin, Kelly sees their offensive line as the "strength of the offense".
If the line is the strength, running back Stepfan Taylor is the major beneficiary of that strength. Taylor, now a senior, has already surpassed the 1000 yard rushing mark for the third season in a row and according to Kelly, will go down as one of the all-time greats at Stanford.
"For some reason, and I don't know why, [he's] an underrated running back. I don't think he gets enough publicity or notoriety for what he's done," he said.
Linebacker Michael Clay says the onus on the defense will be on wrapping up, gang tackling and trying to rip the football loose from Taylor's body. Taking Taylor out of the passing game is also important, as he ranks second on the team in pass receptions.
The passing game has gone under a major overhaul since last season, when the Cardinal featured future first overall pick Andrew Luck. Senior Josh Nunes started the first nine games of the season, but redshirt freshman Kevin Hogan relieved Nunes against Colorado and led Stanford to victory versus Oregon State last weekend.
Hogan is more of a running threat than Nunes was and thus far has exhibited a strong and accurate arm completing 22 of 29 passes for 254 yards in his lone start.
Regardless of the quarterback, Stanford leans on its big and athletic tight ends Zach Ertz and Levine Toilolo. The pair has combined for nine of the team's 16 receiving touchdowns this year and Ertz leads the team with 47 receptions.
"Ertz is kind of unique, in terms of he has the athletic ability to line up at wide receiver, but he's also physical enough to play on the line of scrimmage," said Kelly.
Compared to an Oregon offensive attack that lines up track-speed skill position players and lets them run, the Cardinal and Duck offenses couldn't be more different. That, however, is what should make this match-up so interesting.
"I think they're going to do what we do and we're going to do what we do and we'll see who wins," Kelly said.
Oregon plays Stanford Saturday at 5:00 p.m. at Autzen Stadium. The game will be part of ESPN's College Gameday Tour and will be televised on ABC with Brent Musberger and Kirk Herbstreit in the booth and Heather Cox on the sideline.