The No. 15 Beavers started out the season with Sean Mannion under center. Because of injury they went to Cody Vaz. Then it was back briefly to Mannion. This week it's undetermined.
Other Pac-12 teams that have switched quarterbacks include No. 14 Stanford, which started with Josh Nunes but swapped him for dual threat Kevin Hogan, and beleaguered Colorado, which started the season with Kansas transfer Jordan Webb but is now looking toward Connor Wood and Nick Hirschman.
Washington State has gone back and forth between Jeff Tuel and Connor Halliday.
Injuries are also an issue. Cal senior Zach Maynard is nursing a sprained left knee. Arizona quarterback Matt Scott missed a game with a concussion and might not be back in time to face Utah on Saturday. They Utes are expected to start true freshman Travis Wilson, who unseated Jon Hays.
This week, as Oregon State (7-2, 5-2) prepares to host California (3-8, 2-6), the starting quarterback is still up in the air on both sides.
The Beavers' situation is certainly unique.
Mannion took over the Beavers as a redshirt freshman last season when the team finished just 3-9 overall. He got off to a strong start this year, leading Oregon State to four straight wins while throwing for an average of 339 yards a game.
But Mannion's fortunes took a turn when he injured his left knee on a handoff during a game against Washington State. Two days later, the Beavers announced he needed surgery and the timeline for his return was uncertain. So Oregon State turned to Cody Vaz, who had not started since high school but coolly led the Beavers in victories over BYU and Utah, helping the team to its best start since 1907.
Mannion made an unexpectedly quick recovery and returned to start the next week at Washington. He struggled, however, throwing four interceptions in the Beavers' first loss of the season. So Oregon State turned back to Vaz, who helped the team to a victory against Arizona State.
Vaz started last week in a 27-23 loss to Stanford, but he injured his left ankle during the waning moments. Mannion was taking snaps in practice earlier this week while the Beavers waited to see if Vaz would be cleared.
Oregon State is lucky. Since Vaz had a few quality starts, the Beavers know what they're getting with either quarterback.
"With either guy, we just decide what's going to be best to do against the upcoming team. They're both passers first, the both manage the offense and I think they're both good players," coach Mike Riley said. "They don't really bring something different than the other guy, nor do we have to tone some things down in regard to either guy. That's the beauty of the thing, they both in spring practice and fall camp basically shared the turns for two years. We just run our offense."
On the other side, Maynard was also iffy for Cal. If he can't go, Allan Bridgford will start for the Golden Bears.
If Hirschman isn't cleared from a concussion, Colorado (1-9, 1-6) will start Wood against Washington (6-4, 4-3) on Saturday. Washington coach Mike Leach, who has plenty of other issues to worry about this week, has said he plans to start Tuel this weekend when the Cougars (2-8, 0-7) visit Arizona State (5-5, 3-4).
If Scott can't go for the Wildcats (6-4, 3-4), junior college transfer B.J. Denker will start at Utah (4-6, 2-5).
Probably the most daunting task this weekend belongs to Hogan, who will face No. 1-ranked Oregon at Autzen Stadium.
If the redshirt freshman has any advantage at this point against the Ducks, it may be that last season he led Stanford's scout team in their preparation for Oregon.
"Obviously, you can only do so much in a week. They're doing it all the time," he shrugged. "So it's pretty hard to simulate."
With a victory, Stanford (8-2, 6-1) would claim the Pac-12 North and knock the Ducks out of the national title contention something Oregon did to the then-No.3 Cardinal last season with a 53-30 victory in Palo Alto.
There are still a handful of lucky teams in the league, quarterback-wise. Two of them are in Los Angeles and face off this weekend in a battle for the Pac-12 South.
Senior Matt Barkley hasn't lived up to some expectations this season but still ranks 14th in the nation with an average of just over 297 yards passing per game for the No. 21 Trojans (7-3, 5-3) . He leads the conference with 33 touchdowns, but he's also thrown a league-high 13 interceptions.
UCLA freshman Brett Hundley is not far behind Barkley with an average of 274 yards passing a game for the Bruins (8-2, 5-2).
The other stalwarts among the league's quarterbacks this season are steady Washington junior Keith Price, Arizona State sophomore Taylor Kelly, and undefeated Oregon's redshirt freshman, Marcus Mariota, who is hearing Heisman candidacy whispers prior to his final two regular season games.