Young offensive line will be learning under fire.

Kalen Ballage knows the situation with Arizona State’s offensive line. How the Sun Devils are down four starters from last season. How they’re the least experienced group in the Pac-12.

And yet: “Our offensive line is young, but we’re big up front and athletic,” the junior running back said. “I think it’s just about them getting that game experience.”

ASU opens coach Todd Graham’s fifth season with questions on both sides, but the offensive line might be the biggest. With Ballage and junior Demario Richard in the backfield, the Sun Devils have two explosive backs capable of big numbers — provided they have room to run.

Offensive line coach Chris Thomsen still is evaluating, trying to find the best five, but if the season started Monday, he said he would start senior Evan Goodman at left tackle, sophomore Sam Jones at left guard, senior Stephon McCray at center, sophomore Quinn Bailey at right guard and redshirt-freshman Zach Robertson at right tackle.

Of the group, Goodman is the only returning starter, and he often struggled last season. Combined, the group has 15 career starts, among the fewest in the country, which is why Thomsen said his evaluation will continue even after the season kicks off Saturday against Northern Arizona. “It’s just all a matter of trust,” Thomsen said. “Do you trust guys that they understand what they’re doing when you put them in?”

For Graham’s first four ASU years, he had little turnover along the offensive front. In 2012, he had three starters to replace to start the season. Over the next three seasons, however, Graham never had more than two. Two of those linemen — guards Jamil Douglas and Christian Westerman — are in the NFL, Douglas with the Miami Dolphins, Westerman with the Cincinnati Bengals. A third — guard Vi Teofilo — is trying to make the San Diego Chargers’ roster.

This year’s group will try to establish an identity, learning as they go. A look at the projected starters:

» Goodman. After an up-and-down 2015 season, the 6-4, 300-pound left tackle had a strong summer, changing not only his body but also his approach. He had a strong spring and has followed it with a steady camp, a reason Graham recently signaled him out as the line’s most impressive performer.

» Jones. The versatile 6-5, 297-pound ssophomore started three times last year, mostly at tackle. This year, he’s spent most of camp at left guard. “I think we’re going to be able to run the ball better than anybody thinks,” Jones said. “We do it day-in and day-out.”

» McCray. Although McCray has only one career start, he has experience. In 2014, he took over for injured center Nick Kelly and played more than three quarters against Arizona in the Territorial Cup. A senior, McCray (6-3, 319) also could slide over to right guard.

» Bailey. A sophomore, Bailey (6-5, 307) spent most of the spring and early part of camp at right tackle before moving to right guard. Last year he mostly played on special teams and in jumbo packages. “I like Quinn,” McCray said. “Playing with him is comfortable. Big dude. We work well together with combos and things like that.”

» Robertson. The 6-5, 325-pound right tackle is in line to become ASU’s first redshirt-freshman lineman to start since Evan Finkenberg did so in 2010. What’s impressed Thomsen: Robertson has held his own in practice against sophomore defensive end JoJo Wicker, who Thomsen believes is primed for a breakout season. “Zach’s had a good camp,” Thomsen said. “He really has. He’s a conscientious guy. It matters to him.”

Don’t be surprised to see early changes. Junior-college transfer A.J. McCollum got a late start because of a hamstring issue, but he has impressed Graham the last two weeks, the coach calling him a “throwback” center. If he forces his way onto the first team, ASU could shift McCray to guard.

“He’s a physical, explosive player,” Thomsen said of McCollum. “Plays fast. He’s still learning about what he’s doing in our system because it’s a little different than what he’s used to. Missing the time early in camp has hurt him in that way, and he’s got the conditioning factor as well, just trying to make sure he can play hard for 70-80 snaps.”

Redshirt-freshman Steven Miller, sophomore Alex Losoya and freshman Cohl Cabral also could enter the mix.