We continue our position previews but with the defense, it's a little bit harder to completely categorize each team uniformly so we're going with three groups -- defensive linemen, linebackers and defensive backs.

Yesterday we examined the South's status in the secondary. Today, we're moving on to the North.

Spring position breakdown: Pac-12 North defensive backs, Part I

Cal: At safety, the Bears lost Michael Lowe (graduation) and Avery Sebastian (transfer) and the two main returning options -- Stefan McClure and Griffin Piatt are both spending this spring rehabbing. Not exactly the best situation for a team that desperately needs to build depth in its secondary. But, if there's a silver lining to all of this, it's this: having that many sidelined players certainly opens up a ton of reps at safety for converted quarterback Luke Rubenzer and Cameron Walker. Walker is back at safety after having started eight games at strong safety as a freshman before moving to cornerback last season. Both he and Rubenzer will need to get acclimated/re-acclimated and now, there are plenty of reps to do just that. But, through practices so far, JUCO transfer Derron Brown is looking like he'll be able to make a smooth transition to the FBS level and possibly overtake any of the guys we've already named.

At cornerback the Bears are in much better shape. Cedric Dozier and Darius White Jr. both return, as do Darius Allensworth, Caleb Coleman and A.J. Greathouse. So even with Walker moving back over to safety, they're still in pretty good shape at CB. Though the secondary as a whole will feature a few new faces in 2015, it looks like they're making the right steps to move forward, too. After all, after giving up an FBS-worst 4,406 passing yards (and that's without a bowl game) it'd be hard to take a step backwards.

Oregon: The Ducks secondary will be going through some major transition this spring. It loses cornerbacks Ifo Ekpre-Olomu, Troy Hill and Dior Mathis, as well as safety Erick Dargan, who led the Pac-12 in interceptions a season ago. But safety Tyree Robinson got some good experience there last season (finished with 36 tackles) and will work to solidify himself as the starter for the fall alongside the only returning starter in he secondary, safety Reggie Daniels. A season ago, Daniels finished as the team's third-leading tackler and though there are certainly strides to be made on the field for him, a lot of this spring will be about him filling a leadership void in the secondary. Chris Seisay stepped in for the injured Ekpre-Olomu in the postseason and because of that experience, defensive coordinator Don Pellum considers Seisay to be battle tested. At the corner spot opposite Seisay there will be some interesting competition between Arrion Springs, Mattrell McGraw and early enrollee Ugo Amadi.

Oregon State: First, the good news: One of the two cornerback starters from a season ago is in the Oregon State secondary. Bad news: The Beavers are going through a complete defensive coaching change and need to find players who can not only start, but also several others who can rotate in to Kalani Sitake's defense. Returning starter Larry Scott has the lead at one corner, but nothing is in sharpie yet so expect him to be pushed by the other top three cornerbacks on the Beavers' spring roster -- Dashon Hunt, Dwayne Williams and Charles Okonkwo -- as OSU looks for the top two guys. At safety, it'll be 100-percent turnover and there are only four scholarship safeties on the roster this spring -- Justin Strong, Cyril Noland-Lewis, Brandon Arnold and Adam Soesman. Strong and Noland-Lewis are the obvious frontrunners due to the fact that they've actually been on the field, but with minutes dangling in front of some younger players, don't discount how much someone can step up. But, this is a position to watch this spring as quarterback Tanner Sanders could join the competition. He's not in the running for the QB job so it'd make sense for him to look at a position shift and safety would make sense considering he was actually recruited as a safety by some schools. Will he play here for the Beavers? Maybe.