The Detroit Lions open training camp on July 31 at their practice facility in Allen Park, Michigan. Here’s a closer look at the Lions camp:

Top storyline: This is going to be fairly broad, but the 2017 season seems to be centered around one thing: Can the Lions go from a team trying to squeeze into the playoffs to one that can win the NFC North title for the first time in two decades and a playoff game for the first time in more than a quarter century? Everything around the franchise -- and its immediate future -- probably will revolve around that. There’s a lot tied into that too. Coach Jim Caldwell is entering the final year of his contract, and if things don’t go well this year, what might general manager Bob Quinn do? Caldwell was not Quinn’s hire, and while he appears to have a strong working relationship with Caldwell, would a season missing the playoffs and struggling change his mind? If Caldwell and the Lions are able to make the playoffs again -- and possibly win a division title and/or a postseason game along with that -- the franchise might finally be headed in a direction toward success for the first time since the mid-1990s.

QB depth chart: The starter is set in Matthew Stafford, who is entering his ninth season and on the verge of becoming one of the top 10 quarterbacks in the league. Behind him is the real competition, as second-year pro Jake Rudock and rookie Brad Kaaya will battle for the No. 2 spot -- and possibly only one roster spot. Rudock looked to be well ahead during the spring, but reps and preseason games are going to help determine this competition.

Bubble watch: Offensive guard Laken Tomlinson is going to be one to watch throughout camp. The former first-round pick has $1,212,296 in guaranteed money this season, so the Lions would take a small hit (and a total of $3,451,476 in dead money) if they let him go. With T.J. Lang and Graham Glasgow the probable starters at guard and Joe Dahl an all-purpose lineman who can fill in at either guard spot (or at tackle, in a pinch), it might come down to whether the Lions want to keep five interior offensive linemen. Quinn has shown he’s willing to make tough cuts when necessary, so pay attention to where Tomlinson ends up lining up during camp. Another thing that could factor in is Lang coming off hip surgery. The longer he is not able to practice (he’s expected to be back around the start of training camp), the better Tomlinson’s chances are to be on the roster.

That rookie could start: Barring something surprising, first-round pick Jarrad Davis should be Detroit’s middle linebacker from the get-go. He has taken almost every first-team rep there this spring, and the Lions have said he’s their middle linebacker of the future. Receiver Kenny Golladay is another player to keep an eye on, mostly in three-receiver sets. Golden Tate and Marvin Jones are the starting wideouts, but in a pass-happy offense that often employs three receivers, Golladay should get a lot of early work if he continues to progress from how he performed during spring.

Who, exactly, is protecting Stafford’s blind side? With Taylor Decker out for a while, who protects Stafford’s blindside is a big deal. The Lions have a lot of options -- but all come with questions. Greg Robinson is a former No. 2 overall pick who has the potential, but not the production to be effective. Cyrus Kouandjio should push Robinson, but he is coming off a hip injury. Corey Robinson also is coming off an injury. Cornelius Lucas is the wild card, as he has the most experience in the Lions' offense, although mostly at right tackle; he’s a more natural left tackle and should be in the middle of the competition, as well. But who wins the job is one of the few true starting position battles in camp.

Will the run game finally show up? In all his years as a head coach or offensive coordinator, Caldwell has never had a run game ranked higher than No. 26 in the league, even though he had Ray Rice and Joseph Addai at points in Baltimore and Indianapolis. But Caldwell continues to extol the importance of having a strong run game. The Lions focused a lot of energy on improving the blocking for Ameer Abdullah (signing Lang, Rick Wagner and Darren Fells). Abdullah seems to be fine coming off his Lisfranc surgery last season, and he has shown the promise to be the dynamic rusher the Lions need. The question is whether the Lions will be able to reverse a trend under Caldwell and actually have a strong run game for the first time since Reggie Bush was a 1,000-yard rusher in 2013.

For daily updates at camp, check out the Detroit Lions clubhouse page.