There hasn’t been a shortage of intriguing storylines this spring in the Pac-12. Then again, there usually aren’t. From quarterback battles to disciplinary issues, the 2014 spring has given us plenty to talk about. But which one stands out as the biggest storyline? That’s today’s Pac-12 blog poll question.

What’s the biggest storyline in the Pac-12 this spring?

Your options:

Bralon Addison injury: The Ducks lost one of their top receiving threats when Addison tore his ACL in spring practice. There are options for the Ducks, who are never wanting for offensive talent. But Addison seemed poised to build off an outstanding 2013 after catching 61 balls for 890 yards and seven touchdowns -- not to mention his prowess as a return man. This is the third-straight spring a marquee receiver has gone down (Paul Richardson, 2012; Austin Hill, 2013).

USC quarterback: Cody Kessler is USC’s starting quarterback, for now. New coach Steve Sarkisian announced before the spring game that the incumbent had continued to distance himself from challengers Max Browne and Jalen Greene. It wasn’t a total shock -- given Kessler’s year of experience and the fact that he came on strong in the second half last fall. But USC quarterbacks will always garner national attention.

Quarterback questions marks: While 10 Pac-12 coaches have the luxury of having their QB in place already, two schools are still looking for their starter. Arizona has a host of quarterbacks to choose from. And spring has brought little clarity to the situation. At Washington, Jeff Lindquist and Troy Williams split the snaps, but we won’t know much until Cyler Miles returns from his suspension.

ASU’s defense: Every team has to replace a few key players, but the Arizona State Sun Devils essentially have to replace its entire starting defense. With nine starters gone from last season’s defense gone -- including two-time Pac-12 defensive player of the year Will Sutton -- the competition level was upped to see who is going to step in.

Stanford's RBs: Being a starting running back at Stanford means big production. The Cardinal have had a 1,000-yard rusher every year since 2008, so whoever replaces Tyler Gaffney is probably in for a big season. Though coach David Shaw told the Pac-12 blog earlier this month he’d prefer to have a committee approach, a natural No. 1 will likely emerge. Who that is, however, remains a question.