Left tackle D.J. Humphries (74) and center A.Q. Shipley (53) block during a game last season against the Buccaneers.

INDIANAPOLIS – Steve Keim asks the question, albeit rhetorically, about where the biggest disparity on an NFL field is between positions.

"There is no question it is offensive linemen versus defensive linemen," the Cardinals' general manager said. "(Offensive linemen) have a learning curve against, quite frankly, some of the most gifted athletes in the world, who are 300-pound defensive linemen that move like linebackers.

"There is a huge difference in talent from an athletic standpoint, which reflects in a lot of those defensive linemen's salaries."

It also reflects on the Cardinals' efforts to figure out their offensive line this season.

New coach Steve Wilks has already said multiple times he wants to run the ball first, even in a pass-happy league. The

lines, on both sides of the ball, are his priority.

"As a defensive coordinator, a defensive-minded coach, there is nothing more demoralizing to me than an offense running the ball," Wilks said.

The Cardinals, however, need to figure out who will be blocking. D.J. Humphries is set at left tackle. But the rest of the offensive line generate questions, mostly because of injuries. Center A.Q. Shipley, the one constant the Cardinals had last season, could face a challenge from 2016 fourth-round pick Evan Boehm, a natural center whose time as starting right guard last season did not go well.

Right tackle Jared Veldheer and left guard Mike Iupati are coming off significant injuries as well. Veldheer missed the final three games of the season with a broken ankle (after missing half of 2016 with a torn triceps), and Iupati missed 15 games after tearing his triceps. Humphries also missed 11 games with a pair of knee injuries. Fill-in starters Alex Boone and Earl Watford are scheduled to hit free agency.

The wrecked nature of the line has Keim viewing potential future construction a little differently.

"It's trying to assess across the league, what are the traits a successful offensive linemen have that are playing and playing at a high level," Keim said. "Size, they're smart, they are tough, they are competitive, and more than anything, they are durable.

"We have had a bad run. Mike Iupati having some injuries you couldn't forecast, Jared Veldheer has had injuries you can't forecast, D.J. Humphries who had really started to become an ascending left tackle in this league, has had injuries. When you play an NFL season and finish up with only one starter (on the line) … it really makes you shake your head and try and go back and see what is the problem."

Even if a player can stay healthy, finding draft picks who can contribute the way a team would like immediately can be difficult. The Cardinals have seen that with Humphries and Boehm, for example. Keim said there are linemen coming out in the draft who have only played in two-point stances as opposed to a three-point stance, or never had to huddle.

It's an issue that has been mushrooming over the past several years, and leads back to Keim's theory on OL-versus-DL disparity.

"Offensive line play as a whole is evolving," Arizona State tackle Sam Jones said. "It really comes down to the basics. Technique, and I think the mindset. A lot of college offenses are spread (and) sling the ball, and I can see a lot of those players struggling in the transition."

With those problems stretching league-wide, supply-and-demand also takes its toll in offensive line construction.

"Everyone is going to put an emphasis on having a better offensive line," Keim said. "But there is no doubt across the league that's an area we all need to improve."