When Mike Riley was forced to make the decision on whether to bring back Sean Mannion just a few weeks after knee surgery or stay with Cody Vaz, he referenced the call he made just a few months earlier.

Mannion won the job in fall camp, so it was a clear choice to go back to him now, especially with Oregon State on the verge of accomplishing a first in school history.

"I thought about it in terms of if we were starting over, these two guys were competing. Sean won the job initially," Riley said. "Obviously we feel great about our quarterback situation, it's just a tough decision to make."

With Mannion back in charge, the No. 7 Beavers (6-0, 4-0 Pac-12) come to Seattle on Saturday night to face slumping Washington (3-4, 1-3) with Oregon State seeking the first 7-0 start in school history.

Whether they were the Oregon Agricultural College or any other previous incarnations of the school's name, Oregon State has never won its first seven games to begin the season. And considering the low expectations on the Beavers coming in to this season, a win over Washington would cap a stretch of success that no one outside of Corvallis could have anticipated.

"This is truly a team and they encourage one another," Riley said. "People like (Jordan) Poyer, (Markus) Wheaton and Andrew Seumalo created that energy as the season went on."

Mannion has not played since Oct. 6 against Washington State. He played the entire game against the Cougars, but it was discovered in the days after that Mannion had a minor knee injury that would require surgery. Before the injury, Mannion was among the most impressive quarterbacks in the Pac-12, throwing for seven touchdowns in four games and was averaging more than 339 yards per game passing.

With Mannion sidelined, Vaz stepped in and more than held his own. It was Vaz's passing that led the Beavers to a 42-24 win at BYU, then last week Oregon State relied on its defense in a 21-7 win over Utah. The victory over Utah assured that the Beavers would be going to a bowl game for the first time since 2009 when Oregon State went 8-5 and went bowling in Las Vegas.

But these Beavers do not want their season defined by a 6-0 start.

"I don't think anybody's satisfied with being 6-0," Oregon State receiver Kevin Cummings said. "It's good, but nobody's satisfied."

The Beavers' ability to reach 7-0 may hinge on how well they can control the line of scrimmage on both sides of the ball. Washington's offensive line has been decimated by injuries and quarterback Keith Price continued to struggle last week at Arizona when he committed three turnovers, raising his total to 10 over the past three games.

Because of the injuries to the offensive line, Price has found himself running for safety for much of the season and now comes an Oregon State defense that has 16 sacks with half of those coming from Scott Crichton.

Price's struggles in last week's 52-17 loss at Arizona had Washington coach Steve Sarkisian questioning whether his quarterback was truly trusting the calls that were coming in from the sideline. Repairing Price's trust was one of Sarkisian's tasks this week in the hopes of bringing out the dynamic quarterback who threw for 33 touchdowns a season ago, but enters Saturday with just as many touchdowns (8) as interceptions this year.

Washington is trying to avoid its first four game losing streak since 2009 and has been outscored 128-52 the past three weeks.

"I think we've dealt with some things on our roster this year that could have potentially started that trust to diminish in what's going on around him," Sarkisian said. "But I believe in the way I coach that position. I believe in Keith's ability to play that position. And we'll get it back. I just want to get it back sooner rather than later."

While not the most important individual matchups, the battles between Washington wide receiver Kasen Williams and Oregon State cornerback Jordan Poyer, and Oregon State receiver Markus Wheaton and Washington cornerback Desmond Trufant will feature four of the best skill position players in the conference. Williams is looking to match his breakout game in the Huskies upset of Stanford last month when he had 10 catches for 129 yards and the winning touchdown, but will likely be matched with Poyer, who already has six interceptions.

On the other side, Wheaton has at least 85 yards receiving in five of six games, but hasn't topped the century mark since catching 10 passes for 166 yards against Arizona.

"Being 6-0 is tremendous, man," Wheaton said. "Our hard work is paying off, I will say that."