That now becomes the question -- one that could linger -- about a QB competition that was interesting because it was between a pair of veteran players with experience as successful starters for a nationally ranked team.
Interceptions were a key concern for Sean Mannion last season.
The conventional wisdom was Mannion, now fully healthy, was the favorite. He's bigger and has a better arm and he's a junior compared to the senior Vaz. And the conventional wisdom may have played a role in Mannion getting tapped. The tag goes to talent and youth, of which Mannion had more of both.
"Sean's attributes are obviously his ability to get the ball just about wherever you want on the field," Riley told reporters on Monday. "Along with his knowledge about where we're going and what he should do with the ball."
Mannion's issue has been interceptions. When he throws them, he throws them in bunches. In six games last year, he threw just two picks. In three others, he threw 11. Some of that could be traced to a knee injury. Mannion got hurt during a three-pick game against Washington State, and probably came back too soon in a four-pick game at Washington.
But not all of it. Some of his interceptions were true head-scratchers, particularly if you witnessed his brilliant early work in road victories over UCLA and Arizona.
Mannion threw for 2,446 yards and 15 touchdowns with eight starts in 10 appearances, while Vaz, hampered late in the season by his own ankle injury, threw for 1,480 yards and 11 touchdowns in seven games with five starts.
Riley said he isn't sure whether Vaz will see action against Eastern Washington, but much of that is up to Mannion.
Riley won't play two quarterbacks -- at least during significant action -- if Mannion is lights-out. Or even just productive and efficient. But if Mannion throws a couple of picks, it will be hard to not give Vaz a look.
And therein lies the challenge: You don't want Mannion wincing with every bad throw, worried he'll get the hook. That will make him tentative. But you also don't want to stick with Mannion too long if he struggles.
Put it this way: Say Oregon State is tied with Stanford 10-10 at halftime, but the Beavers left points on the field because Mannion threw two red zone picks. Does Vaz get the call to start the third? Or if not, what if Mannion leads two three-and-outs to start the second half and Stanford goes up 13-10? And Riley hears muttering from his players.
Further, the Beavers have an incredibly back-loaded schedule. That Stanford game is Week 9. The Beavers likely will be favored in their first seven games, so they could play host to the Cardinal at 7-0. That could be a critical top-10 matchup with North Division ramifications. And every game thereafter sets up to be against a potentially ranked team.
So this could get complicated, even well into the season.
On the one hand, the Beavers have a luxury: two competent, experienced QBs. On the other, they have a potentially divisive situation that could become a locker room distraction.