Inside linebacker Shayne Skov has been the literal and emotional center of Stanford's defense for more than two seasons, a mini-mohawked menace who forces opponents to account for him and teammates to follow his lead.
When he went down with a torn ACL during the third game this year, it was a devastating loss for the Cardinal, one that could have derailed their season.
Instead, it became a rallying point.
Relying on its depth and support from Skov during his rehab, fourth-ranked Stanford had one of the nation's best defenses during the regular season, a group that combined with Andrew Luck and the offense to lead the Cardinal to Monday night's Fiesta Bowl against No. 3 Oklahoma State.
"For the first time this year, we actually had some depth on defense and that really showed this year," Stanford linebacker Chase Thomas said. "We didn't really lose a beat, but with Shayne did have that really special ability that garnered attention from every team we played. We definitely felt that loss this season."
With his mini-hawk and smeared-on eye black, Skov has added some edginess to the academics at The Farm. He has the game to back up the braggadocio, too.
Big, fast and with a love of contact, he had an immediate impact at Stanford, playing all 13 games and starting the final seven while finishing third on the team in tackles as a freshman in 2009.
Skov became a dominating force as a sophomore, teaming with Owen Marecic for one of the nation's best pairs of inside linebackers. Skov led the Cardinal with 84 tackles and had 7½ sacks last season, and had a team-high 12 tackles in Stanford's win over Virginia Tech in the Orange Bowl.
With Luck returning for his senior season and Skov anchoring the defense, the Cardinal had their eyes on another BCS bowl, possibly a national title run.
Skov took a big detour against Arizona on Sept. 17.
Moving in to make a tackle in the second quarter, Skov had his left knee buckle when Wildcats receiver Juron Criner barreled into him. Stanford announced the next day that Skov was done for the year, putting the go-hard-all-the-time linebacker on the shelf and likely ending thoughts of heading to the NFL early.
"It's tough _ you can see it a little bit," Stanford co-defensive coordinator Jason Tarver said. "He lives and breathes football."
Despite Skov's injury, Stanford's defense has thrived.
With a powerful front line and depth at every position, the Cardinal had one of the country's best defenses during the 2011 season.
Stanford was fifth nationally against the run, allowing 90.33 yards per game, and was sixth with 38 sacks. The Cardinal also were sixth-best in preventing teams from converting on third downs at 31 percent, 23rd in scoring defense at just over 20 points per game and 25th in total defense, allowing 328.58 yards per game.
Luck and the offense get a lot of credit for Stanford making another BCS bowl appearance, but the Cardinal couldn't have done it without that stout D.
"They are the smartest team we are going to play," Oklahoma State offensive lineman Levy Adcock said. "They are going to be in the right place and the right time and they may be the most physical team we've played."
As for Skov, he's been vigilant with his rehab, helped along with advice from Tarver, who's had a few ACL surgeries of his own.
Unable to help his teammates on the field, Skov has been there for them behind the scenes, attending every meeting and offering advice to younger players when he's not in the gym.
Tarver has tried to keep him involved by asking him how he'd handle certain situations in meetings and film sessions, and Skov joined his teammates in the desert for the bowl game against Oklahoma State.
It's been hard on Skov, who's kept a low profile while rehabbing, and nearly as tough for Stanford's players to see their teammate not be able to play the game he loves so much.
"Clearly he'd love to be out here with us and we'd love to have him," Thomas said. "We hate to see him on the sideline and in meeting rooms not watching him on film, so it's definitely tough. But we know he'll fight back in the offseason after his surgery and get back on track to play in camp."
And Stanford's defense will have its center back.