EUGENE, Ore. -- Starting Saturday against UCLA and continuing next week at Stanford, Oregon faces the most challenging span of its schedule.

The outcome of the seven-day stretch is crucial for the Ducks to have a shot at the national championship. Right now the Ducks sit at No. 2 in the AP Top 25 behind Alabama.

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In the initial BCS rankings released this past Sunday, Oregon is No. 3, pushed back by undefeated Florida State, which beat No. 3 Clemson 51-14 last Saturday.

But while victories against both the No. 12 Bruins and No. 8 Cardinal are considered essential for Oregon, the Ducks are focused solely on UCLA (5-1, 2-1) this Saturday afternoon at Autzen Stadium.

''They're a pretty good team and they have a lot of athletes on that team,'' said Oregon running back De'Anthony Thomas, who is expected to return after missing three games with a right ankle injury. ''They're going to give us their best shot and it should be a good game.''

Ranked No. 21 in the preseason, the Bruins shot up the AP poll with a 41-21 victory against No. 23 Nebraska in Lincoln in the second week.

They fell out of the top 10 after last weekend's 24-10 loss at Stanford. Quarterback Brett Hundley threw for 192 yards and a touchdown, but also threw a pair of interceptions -- including one with a little more than 2 minutes remaining that led to a Cardinal touchdown.

''You want to win these games so bad, so bad. So, you know, we just have to get in the film room. We'll have another opportunity,'' Hundley said afterward. It was the fewest points the Bruins had scored all season.

They'll get their chance for redemption against the Ducks, although UCLA hasn't won at Autzen since 2004. Oregon is favored by slightly more than three touchdowns.

The Ducks have certainly shown very little vulnerability, but their lone win against a ranked team was a 45-24 victory against then-No. 16 Washington at Husky Stadium on Oct. 12.

The Ducks are averaging a little more than 643 yards in total offense and 57.6 points per game, second among FBS-level teams in both categories.

Oregon quarterback Marcus Mariota has emerged as a leading Heisman candidate, averaging 363.4 yards of offense per game. He has passed for 19 touchdowns with no interceptions, and he's run for nine more scores.

Mariota has gone 265 consecutive pass attempts without an interception, an ongoing Pac-12 record that dates to last season. But his concern this week was fumbles, because his first two turnovers of the season came last weekend in Oregon's 62-38 victory at home against Washington State.

One of his fumbles was returned for a Cougar score, and the other led to one.

''Obviously, I have to take care of the ball a lot better. Lucky for us we were able to come out with a win after that, but in these next games we can't have that,'' he said.

Stanford (6-1, 4-1) is in Corvallis this weekend to face Oregon State, which is undefeated after an upset loss to Eastern Washington in the opener. The Beavers (6-1, 4-0) appeared in the BCS rankings at No. 25.

Stanford was No. 6 in the BCS rankings, while the Bruins come in at No. 12.

The weekend will no doubt answer a lot of overall questions in the conference. Last season the Cardinal defeated the then-No. 1 Ducks in Eugene and went on to claim the Pac-12 North before downing the Bruins in the league championship game.

The Ducks' loss to Stanford -- their only one last season -- effectively derailed the team's shot at the national championship last year.

A second consecutive victory against Oregon could help the Cardinal re-establish their standing after a 27-21 upset loss at Utah prior to the win against the Bruins.

But the Cardinal weren't looking ahead, either.

'' We're just looking to go 1-0 every week, so our focus will be on the Beavers this week,'' linebacker Trent Murphy said. ''If we can go 1-0 this week, we'll keep being in good position and end up where we want to be when it's all said and done.''