TEMPE, Ariz. — The Oregon State Beavers have one solid victory, over a Utah team that drubbed UCLA, and one ugly defeat, a 34-3 loss to Cincinnati. They also beat overmatched Idaho State by 51 points.

The Arizona State Sun Devils have beaten three weaklings with one win among them.

It’s fair to say that neither team knows what to expect when they open the Pac-10 season tonight in Sun Devil Stadium.

“We have to prove it,” Oregon State coach Mike Riley said. “There is no announcing how good you are. We have to go prove it. We won’t know until we play this week and then we will go from there.”

Arizona State coach Dennis Erickson has been pleased with his team’s progress over the first three weeks but acknowledges the schedule has been less than demanding.

“Where we are in the Pac-10 ... I’ve said this before, I don’t know,” Erickson said. “We’ve played three non-league games, and so has Oregon State, and you don’t know from week to week. I do know that this game Saturday is going to be by far the toughest game we’ve had.”

Erickson is 3-0 in his first season with the Sun Devils. That has been an unlucky number for recent coaches; in 2000, Bruce Snyder won his first three games, and Dirk Koetter did the same in 2006. Both were fired at the end of those seasons.

Erickson doesn’t have to worry about job security. But he is concerned about which Oregon State team will come to the desert this weekend.

Will it be the Beavers who were embarrassed by Cincinnati? Or will it be the physical team that knocked the Utes’ quarterback out of the game?

“They’re an experienced football team that’s got a lot of guys coming back from the same team that beat us pretty handily in Corvallis last year,” Erickson said, referring to a 44-10 whipping.

The Beavers aren’t very experienced at one important position: quarterback. They are one of two Pac-10 teams, along with Washington, that opened the season with an untested starting quarterback.

Perhaps it’s no suprise that Oregon State’s quarterbacks have twice as many interceptions (8) as touchdown passes (4).

Sean Canfield has cemented his status as the starter after completing 21-of-30 passes for 353 yards and three touchdowns in the rout of Idaho State. Canfield, a sophomore, has completed 58.8 percent of his passes and has four touchdown passes and four interceptions.

“I think he looks good,” Riley said. “Sean was able to make some plays. I think that every time a quarterback can do that, it is a confirmation for him in what he is doing and what we are doing, putting that all together and making some throws.

“Now the competition will increase dramatically,” Riley said. “But he sees that it is all there.”

Another sophomore, Lyle Moevao, has also played in all three games. He has completed 58 percent of his passes but has thrown four interceptions and no touchdown passes.

As for the Sun Devils, their offense has performed well against Colorado, San Jose State and San Diego State, whose defenses rank 69th, 106th and 109th, respectively.

The Sun Devils’ offense is averaging 468.7 yards per game, 24th nationally.

Keegan Herring has rushed for a team-high 256 yards in three games. Quarterback Rudy Carpenter ranks 19th in national passing efficiency. He has completed 61.5 percent of his passes and has seven touchdown passes against two interceptions.

“Offensively we’re getting better because we’re starting to learn the scheme a little bit better and finding out what our strengths are there,” Erickson said. “We’ve made a lot of improvement.”

Starting tailback Ryan Torain, who has been slowed by an ankle injury, practiced this week and is expected to play, as is tight end Brent Miller, who has a knee injury. Neither played against San Diego State.