PORTLAND — This year’s Civil War may go down as memorable for who isn’t on the field, more so than those on it.

Injuries have decimated both No. 18 Oregon (8-3, 5-3 Pacific-10) and Oregon State (7-4, 5-3) in advance of the 111th annual rivalry game this Saturday at Autzen Stadium.

The most notable absences are at quarterback — on both sides.

Oregon’s Dennis Dixon, a finalist for the Walter Camp Football Foundation player of the year award and the Davey O’Brien outstanding quarterback award, tore a ligament in his knee in the Ducks’ 35-23 victory over Arizona State on Nov. 3.

He tried to play on it against Arizona, but it buckled underneath him in the first quarter. The Ducks, then No. 2, lost 34-24 to the Wildcats, lost Dixon for the remainder of the season and fell out of the national championship picture.

Backup Brady Leaf hurt his left ankle versus Arizona and then injured his right in Oregon’s 16-0 loss to UCLA last weekend.

Because third-string quarterback Nate Costa was hurt in practice last month, the Ducks turned to a pair of redshirt freshmen, Cody Kempt and Justin Roper. Kempt will likely start, Roper will be his backup, and the Ducks could turn to tailback Andre Crenshaw in a pinch.

Oregon State will turn to its backup, sophomore Lyle Moevao, to start for the third straight game. Sean Canfield remains out with a shoulder injury.

Moevao, 2-0 as a starter, will be the most experienced quarterback on the field.

“That’s surprising now that I think about it. We thought if anything, Brady Leaf would be playing this week with Dennis Dixon going down in the Arizona game. That’s just how football is. You doesn’t know what to expect,” Moevao said. “Nobody really expected Sean to go down either.”

Earlier this season, the Beavers lost receiver and punt returner Sammie Stroughter because of a bruised kidney.

Several other Beavers are banged up but could play, including defensive end Dorian Smith (sprained knee), offensive guard Jeremy Perry (broken fibula), safety Daniel Drayton (strained groin) and cornerback Keenan Lewis (knee sprain).

The biggest question for Oregon State will be whether running back Yvenson Bernard will play.

Oregon State’s senior tailback, who underwent arthroscopic knee surgery last week, hasn’t been practicing, and coach Mike Riley said his progress is “maybe not as far along as we had thought it might be.”

Still, Riley wasn’t counting him out just yet.

“This is a kind of unusual guy we’re talking about,” he said.

Bernard, Oregon State’s second all-time leading rusher behind Ken Simonton, is 10th on the Pac-10’s career rushing list with 3,685 yards. With another 46 yards he could pass Ricky Bell and Anthony Davis of USC and Gaston Green of UCLA to move into seventh.

Oregon’s situation is much more dire.

Besides Dixon, the Ducks had already lost wide receiver Brian Paysinger for the season with torn knee ligaments, then running back Jeremiah Johnson suffered a similar injury and receiver Cameron Colvin broke his ankle. Linebacker John Bacon tore his ACL and is out for the season.

There is uncertainty about how much tailback Jonathan Stewart will be affected by a sprained toe. While he hasn’t missed any games, he struggled in Oregon’s loss to the Bruins last week.

With all the absentees, the Civil War could be more interesting, Oregon coach Mike Bellotti said.

“You talk about throwing out the records, it doesn’t really matter who is hurt and who is not hurt, who is going to be there or not there,” Bellotti said. “It’s a game that encompasses the whole state, the emotion of it, and somebody’s gonna show up and make some plays that nobody really thought would, or hadn’t heard of before. And obviously we hope it’s a couple Ducks.”