An experienced but thin Arizona State offensive line looked a little shakier than anticipated to start preseason practices on Wednesday night due to a glaring absence.

Senior left tackle Zach Robertson, an honorable mention All-Pac-12 lineman in the preseason media poll, wasn't in attendance. He might not be around any time soon, either.

"Yeah, he's got some personal matters he's dealing with," ASU coach Herm Edwards said following the session. "Whenever he's ready to come back we'll find a way to get him back but right now he could be out for a while."

Senior Cohl Cabral, a Rimington Award Watch List player who excelled at center last season, shifted to left tackle in Robertson's absence. That's where Cabral started for the Sun Devils in 2017 before he shifted to center, where he's better suited to play.

"It's just something that kind of came up last week with things that had happened," Cabral said. "Just made the most of it. Trying to get as much work as I could before today. Today was really kind of going out and trying to get comfortable again.

"All those [personal accolades] are great but the team comes first and that's what it's all about."

The Sun Devils return six seniors in the group but beyond that have almost no experience. The domino effect of shifting Cabral to left tackle included redshirt freshman Jarrett Bell taking first-team reps at center, where he was backed by true freshman Dohnovan West. Both players delivered snaps that were well off the mark in practice, with quarterbacks forced to try to grab balls off the ground and far to the outside of their frame.

That's not a confidence-inspiring thing when ASU is also replacing a veteran quarterback with someone who will have either one career college start, Dillon Sterling-Cole, or a true freshman entering his first college season. Edwards said Robertson's situation is day-to-day but also could conceivably keep him out into the start of the season.

"We're hoping that's not the case," Edwards said of a potential prolonged Robertson absence. "We talked to [Cabral]. For a guy to have to do that who is up for some of the awards that he's in line to receive, it says a lot about who he is. 'I just want to win the Pac-12 South. If I have to play left tackle, I'll go play left tackle.'

"We've become pretty close since the spring. I lean on him a lot. He's one of the leaders. It's good to have a guy like that. He reminds me a lot of (ASU analyst and NFL Hall of Famer) Kevin Mawae. Real thoughtful guy. He thinks about his team."

Cabral may not play left tackle even if Robertson isn't back for the season opener. Offensive line coaches typically experiment with various combinations in camp in order to ascertain what the best options in every injury scenario. That's something Dave Christesen did last August in his first year leading the group and he almost certainly will again in the days and weeks that follow. One possible combination is senior Steven Miller at left tackle with senior Roy Hemsley at right tackle and senior Cade Cote at right guard, with Cabral back at center.

"All those other things are great but the team comes first and that's what it's all about," Cabral said.

For Robertson, this is another in a string of undesirable starts to either spring ball or preseason camp. He didn't play in last season's opener due to a knee injury and drew the ire of coaches in the spring of 2018. He also missed some action at the outset of the 2017 season for team rules violations.

NOTES

-- Junior cornerback Terin Adams entered the transfer portal following his first season at ASU but is still with the Sun Devils. He was dressed out and practiced Wednesday, though not with the first- or second-team.

-- Sophomore tight end/defensive end Mark Walton was not observed at practice.

-- Three players were in green non-contact jerseys: Junior defensive lineman Shannon Forman (unknown), redshirt freshman linebacker Stanley Lambert (recovering from knee surgery in December) and true freshman defensive lineman Stephon Wright (shoulder surgery after last season).

-- ASU was thin at wide receiver after redshirt freshman Geordon Porter pulled up lame with what appeared to be a leg muscle issue and senior John Humphrey appeared to be bothered by some physical ailment. It led to a lot of reps for true freshmen and walk-ons.

-- Junior tight end Curtis Hodges was in attendance but not dressed out and not participating for an unknown reason.