2015 Detroit Lions training camp preview

The Detroit Lions open training camp on Aug. 3 at the team’s practice facility in Allen Park, Michigan. Here’s a closer look at the Lions’ camp, which wraps up on Aug. 19.

Top storyline: Can the Lions build off the first-year success under Jim Caldwell, or was 2014 a singular flash of right things at the right time with a new start? The Lions haven’t had back-to-back playoff appearances since making the postseason three straight times from 1993 to 1995. If Detroit is going to do this, it will be with retooled offensive and defensive lines. The Lions believe that flipping out center Dominic Raiola and left guard Rob Sims for Travis Swanson and Laken Tomlinson will improve athleticism and made the offensive line younger. On defense, though, the Lions lost the heart of their top-ranked run defense with the departures of Ndamukong Suh, Nick Fairley, C.J. Mosley and Andre Fluellen. How the franchise deals with the loss of those players up the middle will be something to watch.

Position battles to watch: Most of Detroit’s starters are set or are expected to be won by rookies once they get settled. This leaves most of the job battles on the periphery. Of the ones out there, the battle for returner between a handful of candidates -- including incumbent Jeremy Ross, rookie Ameer Abdullah and star receiver Golden Tate -- is intriguing. Who starts opposite Haloti Ngata at defensive tackle is important, but the group of Gabe Wright, Tyrunn Walker and Caraun Reid will all have a role in the rotation. Third receiver is also critical, even though the Lions hope tight end Eric Ebron fills that role. It’s a wide-open race beyond Tate and Calvin Johnson that almost any receiver on the roster can win.

Veterans to watch: The vets to watch here are mostly at receiver. The Lions signed Lance Moore in May after he was barely used in Pittsburgh in 2014. He’s no guarantee to make the roster, but if he still has some bounce from his New Orleans days, he could win the No. 3 receiver job. Ryan Broyles is in a contract year and is healthy for a full year for the first time. He’s trying to also win the No. 3 receiver job -- and a roster spot. Defensively, safety James Ihedigbo was fighting for a new contract in the offseason and needs a strong camp and 2015 to potentially earn one. Linebacker Stephen Tulloch is coming off an ACL injury and needs to show he can return to form.

Rookies to watch: This isn’t something to be concerned about yet, but Tomlinson spent most of spring behind Manny Ramirez on the depth chart. He needs to overtake Ramirez over the next month to win the left guard spot. It’d be surprising if he doesn’t. Abdullah should have a role in Detroit’s offense. What it is depends on the health of Joique Bell. Quandre Diggs could surprise and win the nickel corner job. Otherwise, the undrafted rookies who could push for a roster spot are safeties Brian Suite and Isaiah Johnson, running back Zach Zenner and linebacker Kevin Snyder.

Bubble watch: Look mostly at the jumble at receiver, where the Lions have a bunch of guys who are all somewhat similar. Ross, Broyles, Moore, TJ Jones and Andrew Peacock are the names to watch and at least one, if not two, won’t make the team. Special teams matters as much as defensive play at backup linebacker, where a large bubble sits. Travis Lewis, Julian Stanford, Brandon Copeland and Josh Bynes are among the guys all trying to solidify fifth and sixth linebacker spots. Lewis, Stanford and Bynes were all on the roster last season. How they play on kick and punt return and coverage might matter more here.

Replacing Suh: The Lions are sick of talking about it and they insist they have the players to do it, but pay attention to how teams face the Lions early this season. By the end of 2014, teams avoided rushing against Detroit with Suh in the middle of the line. Now, don’t be surprised if teams try to run early right at the heart of the defensive line and at the guy opposite Ngata. He -- and the Lions -- will need to prove themselves against the run again without Suh, and Weeks 2 and 4 (Adrian Peterson and Minnesota, Marshawn Lynch and Seattle) will be early tests of where Detroit’s run defense really stands.

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