The Oregon Ducks and Utah Utes are in a comfortable position with regards to Pac-12 tournament seeding. They have already clinched their first round byes as neither team can finish with no more than six losses, and all but four teams have six losses already. They'll avoid having to play an extra game.
So that leaves three teams vying for two spots: The California Golden Bears, Arizona Wildcats and the Colorado Buffaloes.
Colorado must beat Utah to have a chance. A loss, and Cal and Arizona immediately clinch first round byes regardless of how their weekends go.
The Pac-12 tournament tiebreaker after head-to-head is record against best team in the conference, then second best team in the conference, then third team, etc. etc. With that in mind, a look at the tiebreak scenarios.
If Cal beats Arizona, the Bears clinch their first round bye and at least a 3 seed.
If Cal wins one game this weekend, they clinch a first round bye--they hold the tiebreaker over Arizona by beating Oregon (the Wildcats went 0-1 against the Ducks).
If Arizona and Colorado end up in a tiebreak situation, Colorado wins the tiebreaker over Arizona by winning in their only head-to-head match.
If Cal and Colorado somehow end up in a tiebreaker, Cal could either win a tiebreaker somewhere down the line for beating USC or Washington (Colorado lost to them) or Colorado could win it for sweeping Stanford (Cal split against their rivals).
If Arizona, Cal and Colorado ended up in a three way tiebreak, Colorado wins by virtue of being 2-1 against Arizona and Cal, while Cal and Arizona end up 2-2. Tiebreaking procedures between Cal and Arizona would end with Cal winning the tiebreaker for beating Oregon.
Having the five seed isn't the worst thing: Washington State is awful, and it should be a fairly easy win. But a loss could severely damage tournament standing, and also short circuits their chances at a deep tournament run.
Current tournament seeding
First round byes
First round matchups
#5 Colorado vs. #12 Washington State
#6 Oregon State (based on winning tiebreakers over Stanford & Washington) vs. #11 Arizona State
#7 Stanford vs. #10 UCLA
#8 USC vs. #9 Washington