EUGENE, Ore. — An overstuffed couch. A cool, dark room with the shades drawn. And the door locked.

Who could blame the Oregon quarterbacks for wanting a safe place to spend the remainder of the football season?

The No. 23 Ducks arrive at Los Angeles Memorial Coliseum to play ninth-ranked USC on Saturday amid an incomprehensible, occasionally surgical, rash of injuries.

Seven quarterbacks knocked out of action in less than a year.

The team's defensive leader, defensive back Patrick Chung, calls it God's will, as if describing a tsunami. Offensive coordinator Chip Kelly muses, "It's been interesting to say the least."

With starter Nate Costa gone for the season, Oregon is hoping that second-stringer Justin Roper and his injured knee can be ready for Saturday's game.

If not, the Ducks will continue to alternate between third-stringer Jeremiah Masoli, back from a concussion, and a pair of freshmen.

"It's not fair," Masoli said of Oregon's medical misfortunes. "But every team has to deal with injuries."

So far, the Ducks have gone 4-1, and 2-0 in Pacific 10 Conference play, by compensating.

They will attack USC's suddenly questionable defensive front with the backfield tandem of LeGarrette Blount and Jeremiah Johnson, who have combined to rush for 184 yards per game. The return teams have excelled and the opportunistic defense ranks among the Pac-10 leaders in sacks and interceptions.

"This has been a wake-up call to knuckle down," Chung said. "People had to step up."

But in a conference that lives and dies by the pass, it's hard to look past troubles at quarterback.

For Oregon, the destructive cycle began late last season when Heisman Trophy candidate Dennis Dixon suffered a torn ligament in his knee.

"He was the heart and soul of our team, and it took our guys almost a week to recover," Kelly said. "They realized how much he meant to us."

Oregon, ranked No. 2 at the time, lost three straight games, dropping from the national championship picture. Adding injury to insult, second-stringer Brady Leaf rolled an ankle and his replacement, Cody Kempt, suffered a concussion as the Ducks finished the season with a variety of backups.

This fall, any hopes of a fresh start lasted only a few weeks into training camp as Costa went down with a knee injury. Roper started the opener against Washington and left because of a concussion. He returned for the next two games, then sustained a partially torn ligament in his knee.

Masoli, a community college transfer, stepped in against Boise State and was leveled by a late hit. No one on the sideline realized the extent of his injury until later, when he forgot to send a receiver in motion and called a run play in the wrong direction.

"I can't remember anything from that day," he said.

Freshman quarterback Chris Harper entered the game and struggled, giving way to another freshman, Darron Thomas. The Oregon coaches had hoped to redshirt Thomas but could no longer afford the luxury.

"It's really not fair to the other kids in the program if we're going to prepare for the 2011 season," Kelly said. "The future is now."

All of these injuries have raised questions about Oregon's spread offense, which sends multiple receivers wide, leaving fewer bodies to guard the passer. Coach Mike Bellotti has grown a little tired of questions from the media, insisting that his quarterbacks take fewer hits in the spread than they did when Oregon ran a pro-style offense.

Moreover, he doesn't think they need to take more care on the field.

"You've got to play football," he said.

If nothing else, hardship appears to have strengthened his team's character.

Last week, Blount and Johnson led the Ducks to a 63-14 victory over Washington State by each rushing for three touchdowns. Masoli returned to throw two scoring passes before giving way to Thomas and Harper.

With Oregon sitting atop the Pac-10 standings at this early stage in the season, players say it doesn't matter who lines up at quarterback against USC on Saturday.

They have stopped worrying about a passing game that ranks a mediocre sixth in the conference. They have stopped worrying about injuries.

"When it happens, it happens," Chung said. "Next guy gets ready to go."