What are the three key camp issues facing each NFC North team?

CHICAGO BEARS

Offense: Kyle Long's readiness

The Bears drafted Long in the first round to help an offensive line that has struggled for years to protect quarterback Jay Cutler. Long, however, had a short Division I career and missed almost all of the Bears' offseason work because of the timing of Oregon's final academic quarter. The Bears will find out in camp, and during the preseason, whether Long is ready to be an immediate starter as you would expect based on his draft position.

Defense: Configuring linebackers

After the retirement of Brian Urlacher and the departure of Nick Roach, the Bears gave themselves two tiers of options at linebacker to play alongside Lance Briggs. If all else fails, they can use veteran D.J. Williams in the middle and James Anderson on the strong side. But they also drafted two players who one day will get their chance: Jon Bostic in the second round and Khaseem Greene in the fourth. The process of determining the best combination will begin in training camp.

Wild card: Coaching transition

This will be the Bears' first training camp in 10 years without Lovie Smith as the coach. Marc Trestman began the transition process during offseason workouts, but training camp is the time for establishing the meat of his program. How does he expect players to practice? How quickly does he expect scheme assimilation? How do players know when he's happy? When he's angry? The first training camp will set the parameters.

DETROIT LIONS

Offense: Line changes

One way or the other, the Lions will enter the season with three new starters on the offensive line. Riley Reiff is at left tackle after the retirement of Jeff Backus, and there will be competition at right guard and right tackle. Pulling off an overhaul of the offensive line in a win-or-else season is an ambitious task. All discussion of improvement for quarterback Matthew Stafford, and the impact of newcomer Reggie Bush, is made on the presumption that the offensive line won't take a step back.

Defense: Ziggy Ansah's development

Usually, the No. 5 overall pick of a draft is ready to step in and play right away. But Ansah was a late arrival to football and was almost an unknown to NFL scouts a year ago at this time. There was a sense during pre-draft evaluations that Ansah would need more development time than the typical No. 5 pick, but the Lions have high hopes of putting him into the starting lineup right away. They gave themselves some flexibility by signing free agent Israel Idonije, but they'll find out in camp if Ansah is going to be ready to play a full-time role in Week 1.

Wild card: Ryan Broyles' status

Broyles was a value pick in the 2012 draft, but he is very much needed after the release of Titus Young. Nate Burleson has returned to play alongside All-Pro Calvin Johnson, but the Lions' depth would be thin if Broyles isn't ready to play soon after tearing his ACL in Week 13 last year. The Lions hope Broyles can be full-speed by the start of the season, a pace he must confirm with at least some significant work in training camp.

GREEN BAY PACKERS

Offense: Running back rotation

The Packers added two rookies, Eddie Lacy and Johnathan Franklin, to a group that includes holdovers DuJuan Harris, James Starks, Alex Green and John Kuhn. Unless the Packers suddenly convert to a run-based offense, an impossibility as long as Aaron Rodgers is at quarterback, the Packers will have to thin this herd in training camp. Not everyone from that group will make the team, and a few who do aren't likely to get much action in games. Harris, Lacy and Franklin seem the likeliest candidates -- in that order -- to be feature backs.

Defense: Replacing Woodson

The Packers have openings at safety and cornerback following the release of Charles Woodson. Training camp should provide significant insight, if not an outright answer, into who will start at safety -- M.D. Jennings? Jerron McMillian? -- alongside Morgan Burnett. We'll also get a sense for who is ready to step into the cornerback and nickel job opposite veteran Tramon Williams. Top candidates for that job include Sam Shields, Casey Hayward and Davon House. The Packers' cornerback group is by far the deepest in the NFC North.

Wild card: Crosby's state of mind

No one expects Giorgio Tavecchio to beat out place-kicker Mason Crosby, who went through a well-publicized extended slump last season. But how will Crosby react to the first competition of any sort he has faced since taking over as the Packers' kicker in 2007? That's what the Packers want to find out, frankly. If he isn't sharp in camp, the Packers might need to consider their options elsewhere.

MINNESOTA VIKINGS

Offense: Cordarrelle Patterson's development

The Vikings know they want Patterson to be their kickoff returner, replacing Percy Harvin, but is Patterson ready to take over any part of Harvin's role as a primary offensive playmaker? Patterson's short stay at Tennessee once suggested he will need some development time before contributing regularly on offense. His performance in offseason practices, however, suggested he might be further along than once believed. Training camp will tell us for sure.

Defense: Linebacker alignment

Will newcomer Desmond Bishop play middle linebacker or on the outside? What would that mean for Erin Henderson, who spent the offseason transitioning to the middle position? It seems pretty clear that Bishop, Henderson and Chad Greenway will be the Vikings' three linebackers. Training camp should give us a better idea of where they will line up and, importantly, who will come off the field in nickel situations.

Wild card: Chemistry in passing game

The Vikings are expecting a jump in the efficiency, if not raw numbers, of their passing game this season. Quarterback Christian Ponder will have to accomplish that by developing quick chemistry with his new receivers, including Patterson and veteran Greg Jennings. That task appeared to be a work in progress during offseason practices.