Vaz steps in for injured Mannion

Oregon State coach Mike Riley is notoriously good-natured, even if that quality is measured against the general population and not only from within the grumpy realms of major college football coaches. He tends to maintain a sense of perspective about winning and losing and the ups and downs inherent in his job.

But you can ruin his day and provoke a frown. For example ...

Say it's Monday, Oct. 8. Say Riley is about to preside over a team meeting for the 4-0, 10th-ranked Beavers. And then ...

"The doctor and trainer came running down the hall," Riley said. "I knew something wasn't good."

Correct. Riley's starting quarterback, Sean Mannion, who was passing for 340 yards per game, had a knee injury that no one knew he had when he walked off the field last Saturday after a 19-6 victory over Washington State.

"It was a total shock," Riley said.

There goes Riley's smile. And there goes the season.

Or does it?

That's the big question as the Beavers send junior Cody Vaz out Saturday to make his first career start against a Brigham Young defense that is highly proficient at hitting the quarterback, a nationally ranked unit that has surrendered just nine points in its past three games.

"We don't really have to do anything different with Cody," Riley said. "Cody has been with us a long time."

He then added, "I've got a lot of faith in Cody."

Of course, no one expected anything else but protestations of faith from Riley and his players. There is no other way to be. It's got to be all about supporting the "next man in," or you essentially wave a white flag over what was previously blossoming into a special season.

Further, the injury isn't season-ending. Mannion will have meniscus surgery Wednesday, and his status thereafter will be "week-to-week." While it's purely speculative until the surgery is complete, he could be back in two to four weeks.

So if Vaz can maintain the Beavers' fast start, they might be able to stay in the Pac-12 North Division race.

Riley described Vaz as smart, competitive and talented. He said Vaz has a "great release" and "sees things well."

"He's not much of a different style than Sean," Riley said. "He's just shorter."

Mannion is 6-foot-5. Vaz is 6-1.

The bad news is that Mannion, though just a sophomore, is a veteran who was baptized by a horrible 3-9 season in 2011 that didn't kill him -- despite being sacked 27 times -- and apparently made him stronger. Past history has shown that quarterbacks tend to make great strides in their second year playing in Riley's system, but the first year is often filled with pratfalls.

Vaz will not only be making his first start, he will be seeing his first college action since getting some throw-away time in 2010.

"The only unfortunate part is I haven't played him enough," Riley admitted.

Still, BYU -- hardly an offensive juggernaut in any event -- has quarterback issues itself. Talented freshman Taysom Hill had played well filling in for injured senior starter Riley Nelson, but he blew out his knee last week late in a 6-3 win over Utah State. Nelson will get the start against the Beavers, but he's coming back from fractured vertebrae.

The best part of Nelson's game may be his athleticism, but a back injury isn't something you want to test with a lot of QB scrambles.

Oregon State has played good defense this season, particularly against the run. It also has a strong secondary that has grabbed seven interceptions. While Riley maintains that the playbook will be open for Vaz, it wouldn't be surprising if the Beavers leaned on their defense and hoped their running game got untracked.

Unfortunately, the running game remains a work in progress for Oregon State. The previous two seasons, it was horrible. This year?

"It's OK," Riley said. "We've gotten better for sure from a year ago. I wouldn't say it's reliable."

Did we mention that BYU is No. 1 in the nation against the run, yielding just 1.93 yards per rush?

Vaz has looked good in practice. In fact, he has looked like the Beavers' best signal-caller at times. Riley's comments last spring suggested that Vaz had gained on Mannion. While Riley said Tuesday that he "never made the point that there was an imminent change," he said that Vaz was good enough to make it clear that the competition "was real."

"The one good thing about this on our team is they all know Cody is good," Riley said.

Good in practice is one thing. Good in front of 63,500 fans at LaVell Edwards Stadium is another.