Last year, we looked at returning 3,000-yard passers, so the headline here shows how the Pac-12 has become more run-based, defensive minded of late.

And, of course, the conference's top two passers, Arizona's Matt Scott and USC's Matt Barkley, are both off to the NFL.

The returning members of the 2.5 K Club are:

• UCLA's Brett Hundley (3,740 yards, 29 TDs, 11 Ints, No. 4 in passing efficiency)

• Arizona State's Taylor Kelly (3,039 yards, 29 TDs, 9 Ints, No. 2 in passing efficiency)

• Washington's Keith Price (2,728 yards, 19 TDs, 13 Ints, No. 8 in passing efficiency)

• Oregon's Marcus Mariota (2,677 yards, 32 TDs, 6 Ints, No. 1 in passing efficiency)

There's a reason why Oregon, UCLA and Arizona State are highly thought of heading into 2013: Proven production returning behind center. And if Washington can get Price back to top form, the Huskies become a top-25 team.

So how does everyone else stack up? Which teams seem likely to get 2,500 yards passing next fall?

Well, there's lots of "To be determined" intrigue.

TBD, Arizona: B.J. Denker will enter fall camp atop the depth chart, but this one is far from over. If USC transfer Jesse Scroggins, who owns by far the biggest arms on the roster, wins the job, the Wildcats are almost sure to pass for 2,500 yards. Coach Rich Rodriguez, though widely viewed as a spread-option coach, showed last year he's comfortable throwing, so Denker or incoming freshman Anu Solomon also could put up solid passing numbers.

TBD, California: New coach Sonny Dykes likes to throw the rock around. Louisiana Tech averaged 351 yards passing per game last year. So whoever wins the QB job -- we're betting on Zach Kline -- will almost certainly hit the 2,500-yard mark.

TBD, Colorado: The Buffaloes struggled to the throw the ball last year, but new coach Mike MacIntyre might solve that, seeing his San Jose State Spartans passed for 332 yards a game last fall. Connor Wood, the frontrunner to win the job, has the arm to throw the ball around, but it's a matter of putting it all together.

TBD, Oregon State: Sean Mannion nearly made the above list, passing for 2,446 yards and 15 TDs with 13 interceptions last year, ranking fifth in the conference in passing efficiency and fourth in passing yards per game with 244.6. But he's still knotted with Cody Vaz in the competition for the starting job. If one guy starts the entire season, he will put up strong passing numbers because Mike Riley teams always do.

Kevin Hogan, Stanford: The Cardinal ranked 10th in the conference in passing last year with just 200 yards per game, but part of that was a scheme that played to a rugged defense and Hogan not winning the job until after midseason. Hogan is plenty capable, and his supporting cast is solid. Expect Hogan to at least hit the 2,500-yard mark.

TBD, USC: Whether it's Cody Kessler or Max Wittek, the USC QB will throw for at least 2,500 yards if he maintains his hold on the job. While Lane Kiffin likes balance, there are too many passing game weapons not to attack downfield, starting with All-American receiver Marqise Lee.

Travis Wilson, Utah: The Utes were last in the Pac-12 and 97th in the nation in passing in 2012, but Dennis Erickson is now their co-offensive coordinator. One of the original architects of the spread passing attack, it's highly likely Utah will substantially boost the 190.7 yards passing a game it produced last fall. Wilson is fully capable of throwing for 2,500 yards, and the Utes are solid at the receiver position.

Connor Halliday, Washington State: Halliday still isn't free-and-clear of redshirt freshman Austin Apodaca, but he's a solid frontrunner in the competition. Whoever wins the job, he will put up big numbers in Mike Leach's "Air Raid" system. The Cougars couldn't stick with a QB last year, going back and forth with Halliday and Jeff Tuel, but they still led the Pac-12 with 330.4 yards passing per game. If Halliday starts 12 games, he'll throw for 4,000 yards.