GREEN BAY, Wis. -- The Green Bay Packers open training camp July 27 at their regular practice facility across from Lambeau Field. Here's a closer look at the Packers' camp:

Top storyline: The Packers' revamped defense under new coordinator Mike Pettine will be under examination during each and every practice. The early returns in OTAs were strong; during one of the public practices, it picked off Aaron Rodgers twice. Granted, those were not padded practices. Certainly there will be days when Rodgers and the offense pick apart the defense, but once the pads go on, the real evaluation of the unit begins in earnest. It will be worth watching where the pass rush comes from considering that beyond Clay Matthews and Nick Perry, there are no proven outside rushers. Perhaps the addition of defensive tackle Muhammad Wilkerson will improve the interior rush. The cornerback position also has been revamped with the signing of veteran Tramon Williams and the addition of the top two draft picks, Jaire Alexander and Josh Jackson.

QB depth chart: For now, it's still Brett Hundley behind Rodgers. But don't be surprised if at some point during training camp DeShone Kizer emerges as the No. 2. Hundley will get his chances to prove he's better than what he showed last season when he made nine starts after Rodgers broke his collarbone, but the trade for Kizer (who started 15 games as a rookie last season for the Browns) showed a clear intent to upgrade the backup spot in case something happens to Rodgers again. Undrafted rookie Tim Boyle is the No. 4 entering camp.

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Bubble watch: This isn't so much a bubble watch but rather an injury watch that could turn into a major roster decision on Bryan Bulaga. The veteran right tackle probably won't be on the field for the start of training camp; he'll likely start on the physically unable to perform list while still rehabbing a torn ACL suffered in November. It also might be a long shot for him to be ready to start the season. If the Packers feel good about the addition of veteran Byron Bell and the depth Jason Spriggs and Kyle Murphy provide, then perhaps they'd move on from Bulaga even when he's ready to go.

This rookie could start: Either Alexander or Jackson had better start. That's why new general manager Brian Gutekunst used his first- and second-round picks, respectively, on the pair of cornerbacks. If Kevin King and Williams man the outside positions, then perhaps Alexander could start in the slot in the nickel package.

Running back by committee: The great thing about having three capable running backs is that if one runs into trouble or gets injured then there are options. The flip side is it could take away from the rhythm of the offense if the back changes every couple of series. So Packers coach Mike McCarthy will have to sort out how he plans to use Ty Montgomery, Jamaal Williams and Aaron Jones, all of whom played the No. 1 role at different times last season.

The Philbin effect: Training camp should shed some light on what the return of offensive coordinator Joe Philbin means for that side of the ball. Philbin, during his previous stint in that job, was the perfect muse for McCarthy when it came to deciding what's good -- and more important, what's bad -- about the offense and play selection. He has the respect of Rodgers, who has already raved about Philbin's impact.