Defensive tackle, nickelback among Detroit Lions' unsettled positions

Unlike some other years for the Detroit Lions, the franchise can look and feel comfortable that barring injury, most of the starting lineup is set entering next week’s 2015 training camp.

There are still some places open, though, and some battles to watch.

One of the biggest is at defensive tackle, where Haloti Ngata is set at one spot and the other one is wide open. Then there are the situations at running back, strongside linebacker, nickelback, third wide receiver, kick and punt returner, left guard and the fourth offensive tackle.

Not all of these positions are high-profile, but that’s not a bad thing for a franchise that is trying to make back-to-back playoff appearances for the first time since the mid-1990s, when the Lions made three straight trips.

So here is a brief primer on what to look for at each of the defensive and specialist position battles entering training camp, starting with those defensive tackles.

Tyrunn Walker vs. Caraun Reid vs. Gabe Wright: One of these three will end up starting next to Ngata. All three will likely play a role, and at least two of them need to be strong pass-rushers to help the ends and linebackers. The early favorite is Reid, mostly because he lined up with the first unit throughout much of the spring, but until he puts pads on and actually hits, it is tough to know what he will be able to do. Walker was signed to be the likely starter, and it will probably come down to one of those two guys. There is room for Wright, but the only way he starts is if both Reid and Walker falter or he surprises everyone in camp. Gut pick: Walker.

Tahir Whitehead vs. Kyle Van Noy: Another scenario where both men end up on the roster. The prize here is less special teams work, though. Though both will almost definitely play on various teams, the loser of the competition is probably a four corps special teamer in 2015. Though this might not change a 2015 decision, this is a contract year for Whitehead and that’s worth monitoring as well -- especially if he loses the job and Stephen Tulloch plays well. Gut pick: Whitehead.

Josh Wilson vs. Quandre Diggs vs. Nevin Lawson: With the release of Bill Bentley, the nickelback role became a three-man competition, and in Wilson and maybe Lawson’s case, a fight for a roster spot. Diggs was a small surprise during spring workouts, essentially splitting time with Wilson as the top nickelback. Provided Lawson is healthy, pay attention to the early snaps here. If Lawson starts stealing first-team reps along with Diggs, it could put Wilson in a tough spot. Just as likely is Wilson winning the job. Gut pick: Diggs.

Jeremy Ross vs. Ameer Abdullah vs. Golden Tate vs. Ryan Broyles: There are more candidates here, but these four are going to receive the most attention at first. Ross is the incumbent, but Detroit made it clear throughout the offseason it would at least investigate finding an upgrade to return punts and kicks. Part of that was drafting Abdullah, who is also vying for running back snaps. Those two are the favorites. Tate could end up as the punt returner, but it would be extremely shocking if he also returned kicks. Considering his importance to the offense, even seeing him return punts would count as a mild surprise, even if he is the best returner on the roster. The last time Broyles returned a punt in the regular season, he injured his Achilles. But he was back there working with the other returners, and for someone who is finally healthy and in a close battle for a roster spot, showing he has the want-to and the flexibility to return could help him immensely. Abdullah missed a couple catches during the spring, but once pads are on it should be back to normal for him. Gut pick: Abdullah.