EUGENE, Ore. >> Back at the start of the season, Oregon’s game at USC was circled on lots of calendars.

It appeared at the time to be the marquee matchup of the Pac-12 season, as well as a possible preview of the league championship game, with the Trojans entering the season ranked No. 1 in the preseason poll and Oregon ranked fifth.

Adding to the anticipation was USC’s 38-35 upset victory over the Ducks at Autzen Stadium last season.

Eight weeks later, the shine is off the game a bit. USC has lost two games, including a 39-36 loss at Arizona last weekend, and fallen to No. 18 in the AP rankings.

Undefeated Oregon has climbed to No. 2 and has taken aim at a second national championship berth in three seasons. The Ducks are leading the nation with an average of 53.38 points per game. Their vaunted offense is ranked third with an average of 331 yards rushing and seventh in total offense with 540 yards on average.

Oregon hasn’t dropped a game since that loss to the Trojans last season, a string of 11 straight victories.

So it follows that the Ducks (8-0, 5-0 Pac-12) are favored to win Saturday night’s game in Los Angeles.

But don’t count out USC just yet, warned Colorado coach Jon Embree, who has seen both teams.

“With a team like that, you’d rather play them after a win than a loss,” Embree said. “They’re going to come out fighting and with a different sense of purpose.”

Colorado is the most recent team to fall to the Ducks, losing 70-14 last weekend at Autzen Stadium. The Buffaloes, with just one win this season, really never stood a chance with Oregon leading 56-0 at the half and eventually piling up 617 yards in total offense.

Earlier in the season, the Buffaloes lost to the Trojans 50-6 in Los Angeles. USC quarterback Matt Barkley tied his school record by throwing for six touchdowns.

Washington coach Steve Sarkisian, whose Huskies have also faced both teams — and also lost to both in back-to-back weeks — wasn’t willing to pick a winner.

“I think it will be a good game,” Sarkisian said. “I think they’re different in their style and their approaches. But they’re both good teams, both well-coached. It will be a fun game to watch.”

USC’s loss to the Wildcats changed the tone of the season for the Trojans, who were picked in the preseason to win the conference championship and now sit at 6-2 overall and 4-2 in the conference.

The Trojans still lead the Pac-12 South after Arizona State’s loss to UCLA at home, but they lost a chance to get some separation. They also lost any realistic hope of playing for the national title.

Still, USC did put up some impressive offensive numbers against Arizona, including Marqise Lee’s Pac-12-record 345 yards receiving on 16 catches, along with two touchdowns. Lee was named the Pac-12 player of the week.

Barkley threw for a school-record 493 yards and three touchdowns as the Trojans rolled up 618 yards.

But the Trojans hurt themselves with 13 penalties for 117 yards. USC has been the most penalized team in the Football Bowl Subdivision, with 10.25 penalties for 84.63 yards per game.

In contrast, Oregon blanked Arizona 49-0 earlier this season.

“Both teams have great athletes on both sides of the ball, and certainly a lot of guys that are going to be playing on Sunday,” Arizona coach Rich Rodriguez said. “Oregon’s philosophy is to try to go faster offensively, at a different tempo than USC goes, but I think it’s going to be a great ball game.

“You’ve got a lot of veteran players that understand their systems and it seems that both teams are pretty healthy going into it. We didn’t play well at all against Oregon, of course, but there were moments we didn’t play well against USC.”

Even though the Trojans aren’t living up to expectations, they’re still playing for the Pac-12 South and a spot in the league championship game on Nov. 30 — where they could face Oregon again. And a USC upset for the second straight season could derail the Ducks — again — in a bid for a national title.

Oregon’s players are aware of what’s at stake.

“This game has been hyped all season and it’s finally here. But we couldn’t focus on them the whole year because then we wouldn’t be where we are,” Oregon safety Brian Jackson said. “So now it’s time to focus on them and they definitely have our attention.”