ALLEN PARK, Mich. — The Detroit Lions have assembled one of the most talented rosters in football. But as we saw last year, talent can only get you so far.Health, quality depth, growth from young players — all necessary. Across the board, really.But when evaluating this team, certain positions give you pause. The Lions need favorable outcomes there more than others. They’re the groups that, in many ways, could make or break the season.Let’s talk about it.Running backIf you’re not used to seeing the running back position here, grab a ticket and join the line. For three consecutive years, the Lions had the best RB tandem in the NFL. Jahmyr Gibbs and David Montgomery combined for 7,652 scrimmage yards and 82 touchdowns in the regular season during their run in Detroit. You could sleep peacefully knowing the Lions were in good hands at one of the most injury-prone positions in football. But that sense of security is now one play away from vanishing.Montgomery is off to the Houston Texans after an offseason trade. The team hoped to account for Montgomery’s departure by signing Isiah Pacheco to a one-year deal, but Pacheco missed weeks of practice with a sprained MCL, then picked up a back injury. He’ll miss at least the first four games of the season after being placed on injured reserve. There is no timetable for his return.This is life in the NFL, but the Lions were living a sheltered one for years. They’ll lean on Gibbs as their bell-cow running back, and after last season, it’s wise to do so. He’s the most explosive back in football, and he’s signed for the long haul. But at 5-foot-9 and 202 pounds, is Gibbs built to handle a top-five workload? He ranked 17th in attempts per game in both 2024 and 2025. He’s young enough to handle more, but it does give you a bit of pause. If Gibbs goes down, the Lions will be left with Sione Vaki (seven career carries) and Jacob Saylors (two career carries), with Pacheco out. They no longer have the luxury of Montgomery.Gibbs is tougher than he looks for a smaller back and has proven to be durable throughout his career, but it’s at least worth mentioning as he takes on a new role with more touches. This offense runs through him.Offensive lineThis offseason, the Lions promptly addressed an offensive line in need of retooling. They moved on from veterans Graham Glasgow and Taylor Decker — replacing them with Cade Mays (three-year, $25 million contract in free agency) and first-round pick Blake Miller. Penei Sewell moved from right tackle to left. Second-year guard Tate Ratledge is back for more. And the Lions brought in veteran Ben Bartch to compete with left guard Christian Mahogany, and Larry Borom as starting-caliber depth at tackle.Where does that leave the room now that the season is almost here?Mays is shelved until mid-October at the earliest. The Lions are rolling with Juice Scruggs — who reacclimated to center in training camp — until further notice. Miller went through predictable rookie struggles in camp, and the Lions didn’t make it much of a battle, relegating Borom to the second-team offense early in camp. Bartch missed extended time with a foot injury and a concussion. Without the necessary practice time to compete for the left guard job, Mahogany enters the year as the default starter. If Miller looks like a rookie, Scruggs can’t hold up at center and Mahogany and Ratledge don’t take the necessary leaps, this unit could look a lot like it did last year. We saw how that went.If you’re an optimist, you’ll buy that Miller, whose growth from OTAs to training camp has been praised, will only improve as he gains valuable game reps. His athleticism will be an asset in the screen game and on tackle pulls, which we’ve already seen in practice. Settling the right tackle job early in camp allowed Miller to develop chemistry with the starters and gives you a veteran backup in Borom who knows his role. Mays offers the size and anchoring ability in the interior the Lions covet. He should be able to protect Jared Goff in ways the Lions couldn’t last year. His backup, Scruggs, is a natural center who might’ve started over Glasgow a year ago. Ratledge is looking like an ascending player in his second year, mentioned in the same breath as core players by coach Dan Campbell. Mahogany, despite not being pushed, has looked the part in his third year and will be playing alongside an All-Pro in Sewell and an upgrade at center in Mays when he returns.Which version of the offensive line will we get? The answer will go a long way toward determining how efficient this offense is.Take a tour of the food and drink options at Ford Field this NFL seasonColton PouncySecondaryThree of Detroit’s four 2025 starters in the secondary — four of five if you include the nickel position — won’t take the field for the Lions in their season opener Sunday against the New Orleans Saints. Amik Robertson left for the Washington Commanders in free agency. Former first-round pick Terrion Arnold was arrested and released this offseason. And starting safeties Kerby Joseph (knee) and Brian Branch (Achilles) will begin the year on IR and miss at least the first four games. Naturally, it’s created some uncertainty.D.J. Reed returns as the lone holdover as a starting outside corner — in the second year of a three-year, $48 million contract. After dealing with a hamstring strain last season, the Lions need Reed to play like a CB1. He had been one of the league’s most consistent cornerbacks prior to arriving in Detroit, so the talent is there. We have to see it in 2026.Rock Ya-Sin is the projected starter opposite Reed. After signing a one-year deal with the Lions in 2025, Ya-Sin performed above expectations — allowing a passer rating when targeted of 74.1 across 16 games. The question with Ya-Sin will be consistency. He’s 30, and the position is volatile. Can he provide the same baseline of play over 17 starts?And finally, at safety, the Lions are patiently waiting for Branch and Joseph to return. When might that be? Depends who you ask. Campbell initially thought Branch and Joseph would return to practice in late August or early September. We’re on the tail end of that window now, and Lions general manager Brad Holmes didn’t have an updated timetable for either player. They’re not eligible to play until October, anyway.A lot of unknowns here.Best-case scenario: The supporting cast of Chuck Clark, Avonte Maddox and Roger McCreary hold down the fort until Branch and Joseph return. Reed plays up to his contract. Ya-Sin offers excellent value as a CB2. Branch looks like himself immediately, giving the Lions an All-Pro-caliber DB. Joseph, even if he has to manage his knee, is still capable of creating turnovers and forcing QBs to second-guess throwing his way. The Lions have more than enough in the secondary.Worst-case scenario: Reed struggles again. Ya-Sin’s production declines when asked to play more snaps. Clark and Maddox are liabilities at safety. Branch struggles to shake off the rust. Joseph’s knee remains an issue. QBs feast on this secondary.Defensive lineGiven the secondary concerns, the Lions could need a big year from their defensive line — making it one of the most important groups on the roster. You could say that every season, of course, but the Lions haven’t had depth like this every season.Aidan Hutchinson, at this stage of his career, is a perennial 12-sack, 100-pressure performer when healthy. That feels like the baseline. He hit 14.5 sacks last season, and could’ve had more if not for some sack-negating penalties. What he offers in the room makes life easier for those around him. The Lions believe they have the necessary pieces around him.DJ Wonnum gives them a high-floor, veteran edge who can do a little bit of everything. The last time Wonnum played with an edge like Hutchinson, he turned in a pair of eight-sack seasons with the Minnesota Vikings, along with above-average run defense. Wonnum says this is the best training camp he’s had in years, and he’s eager to prove he can do damage on his own — not just because of Hutchinson. Factor in Tyler Lacy on run downs and rookie second-rounder Derrick Moore on third downs, and the Lions have a little bit of everything in the edge room. Not to mention Alim McNeill is another year removed from a torn ACL, 2025 first-round pick Tyleik Williams is expected to take a leap and rotational three-techs Levi Onwuzurike, Skyler Gill-Howard and Mekhi Wingo.The Lions recorded the third-slowest average time to pressure last season. They have to be better this year to get where they want to go. If the Lions can generate enough collectively and quickly, it can have a trickle-down effect on the secondary and give the defense a chance to compete. If not, things could look ugly.