INDIANAPOLIS (AP) — Tony Romo. Andrew Luck. Joe Flacco. Andy Dalton. Ben Roethlisberger.

They’re all quarterbacks who have either won a championship or been picked for multiple Pro Bowls. They’re also guys who missed four games or more in 2015.

The importance of keeping the quarterback from serious injury has long been obvious, and that was never more apparent than last season. So guess which position group will be as scrutinized as much as ever this spring?

“All the way through the National Football League, everyone is concerned about their offensive line,” Seattle general manager John Schneider said. “If you talk to college coaches recruiting high-school kids, they are concerned as well.”

Thus, this promising collection of prospects could hold some of the keys to improvement for several teams. Mississippi tackle Laremy Tunsil has been widely projected as the first overall pick in the early, endless waves of mock drafts. Tackles such as Ronnie Stanley (Notre Dame), Taylor Decker (Ohio State) and Jack Conklin (Michigan State) are also legitimate first-round candidates, as is guard Cody Whitehair (Kansas State).

“Being the No. 1 pick would be great,” Tunsil said, before expanding on his goal: “I’d love to play for any team.”

As the least-glamorous position on the field, excluding special teams, offensive linemen won’t make many of the headlines at the NFL scouting combine this week. They’ll play a critical part in the evaluation of this rookie class, though. With the proliferation of elite pass rushers, the right tackles have become as coveted as the left tackles. Guards and centers are critical components, too.

“The quarterback is the most important position on the team. It’s imperative you keep him upright and keep him able to throw the football,” said Tennessee general manager Jon Robinson, whose team has the first selection in the draft.

If the Titans stay in their spot and take Tunsil, he’ll be the second tackle in four years to go first overall. Eric Fisher (Central Michigan) was drafted by Kansas City, followed by Luke Joeckel (Texas A&M) to Jacksonville in 2013. Nine offensive linemen were first-rounders that year. There were five of them in 2014, when tackle Greg Robinson (Auburn) was taken by St. Louis at No. 2. Seven offensive linemen were selected in the first round in 2015.

“I’ve always been told that an offense and a team is not any better than its offensive line,” UCLA center Jake Brendel said. “I feel like that’s something that’s even been exemplified even more at the pro level, for sure.”

Depth is crucial.

“Every year when it comes down to the 53-man cut down, that’s maybe the most active position people are looking for,” Minnesota general manager Rick Spielman said, adding: “If a team thinks an offensive lineman has a chance he’s probably going to get claimed, so you’re very guarded on a guy who may not be ready but has upside, but he’s going to take time to develop. You want to try and keep those guys, because if you get rid of those guys and you get injuries up front, I think it really hurts your football team.”

The evaluation process has been complicated by the trend toward spread offenses in college. The majority of blockers have been zone blocking out of two-point stances, rather than powering ahead out of three-point alignments.

“You really have to dig through those plays where you can really see him unroll his hips and dig his cleats in and really get moving,” Arizona general manager Steve Keim said, adding: “offensive linemen as a whole are hard to find. You look across the National Football League and you see some talented players. Yet at the same time, there’s some parity, some overachievers, some tough guys with intangibles, whether their smarts, their passion for the game, their toughness.

“Supply and demand at that position is extremely tough, because so many qualities at the position come into play.”

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