Arizona - RB Pierre Cormier (redshirt)
The Wildcats will use a community of unproven talents to try and fill in for Ka'Deem Carey and the speedy Cormier is the pick of many to be the leader of that group of talents. Cormier was a heralded recruit coming out of high school and the Wildcats had the luxury of redshirting him with Carey and senior Daniel Jenkins on the roster in 2014, but they will probably unleash him on the conference this season as a feature back.
Arizona State - S Marcus Ball (redshirt)
I actually featured Ball in my post about 2014 Pac-12 breakout stars, so it's not surprising that he is my choice for Arizona State's impact freshman. He was poised to be the starting safety opposite Alden Darby for the Sun Devils in 2013 before a preseason injury forced a redshirt, so expect him to start and make a major impact if he can stay healthy this time around as a freshman.
Cal - CB Darius Allensworth (redshirt)
The Bears are seriously hurting for cornerbacks after injuries depleted their secondary in 2013 and starter Kameron Jackson departed for the NFL a year early. Allensworth was one of top recruits in Cal's Class of 2013 and is fighting it out with a number of other underclassmen for one of the starting cornerback positions and looked to be a favorite to win one of the spots coming out of spring.
Colorado - DE Derek McCartney (redshirt)
Bill McCartney's grandson is making a quick impact after redshirting as he impressed during spring practice and has a good shot at starting at defensive end in 2014. The Buffs have been weak up front in recent seasons, but McCartney could bring some strength to the position and quickly develop into a stalwart on the edge.
Oregon - WR Devon Allen (redshirt)
The Ducks have a number of freshman receivers who are going to have to step up in the absence of Josh Huff and Bralon Addison and Allen impressed the most of any in the group during spring. He is a long target with excellent speed and athleticism that broke out in Oregon's spring game with two touchdown catches.
Oregon State - CB Dashon Hunt (redshirt)
Not a ton of opportunities for freshman with the Beavers this year as they broke in a lot of youth in 2013, but Hunt could compete for the starting cornerback spot opposite of Steven Nelson. He is undersized, but explosive and can bring the kind of aggression to the position that has made Jordan Poyer, Rashaad Reynolds and Nelson All-Pac-12-level corners.
Stanford - TE Dalton Shultz (true)
Stanford went from getting the most production out of their tight ends of about program in the country in 2011 and 2012, but completely fell off the map in 2013, but they were able to land Shultz, the top rated tight end prospect in the Class of 2014. Shultz is a natural pass catcher that might take a while to get up to snuff for Stanford's blocking scheme but could make an instant impact as a receiving tight end as a true freshman.
UCLA - WR Eldridge Massington (redshirt)
Massington was a big time recruit in the Class of 2013, but the Bruins were able to redshirt him with their massive depth at receiver in 2013, especially with Shaquelle Evans and Jordan Payton filling the big receiver role. The Bruins have a wealth of talented receivers, but no stars (especially with Evans off to the NFL) and Massington has just as much potential as the rest of their young receivers to be that go-to receiver with his size (6'3 215) and athleticism.
USC - G Toa Lobendahn (true)
The Trojans are incredibly thin on the interior of their offensive line, so it was a serious boon for them when elite recruit Lobendahn enrolled early for spring and looks like he could start at guard as a true freshman. He is a superbly polished player for someone who should be in high school that could help keep the Trojan run game healthy even with the loss of Marcus Martin.
Utah - RB Troy McCormick (redshirt)
Bubba Poole will likely be the starter for Utah, but they need someone to fill his former role as the second back and McCormick looks like he might be that guy in 2014. He impressed in the spring with his speed and ability to crack big runs on any carry.
Washington - QB Troy Williams (redshirt)
The Huskies might not have a definite starting quarterback until a ways into the 2014 season and coming out of spring, Williams is right in the hunt for winning the job. Even if he doesn't win the starting job in fall camp, expect him to play at some point, especially since expected Husky starter Cyler Miles might be suspended for a portion of the season.
Washington State - CB Charleston White (redshirt)
Washington State graduated almost their entire starting secondary and burgeoning star sophomore corner DaQuawn Brown may be suspended at the beginning of the season due to off-the-field issues so they are really hurting for defensive backs right now. It is a free-for-all right now at corner for the Cougars with a number of redshirt freshmen competing for starting spots and right now White looks the most poised of any of them to win the job.