It might have helped the depth in Stanford’s beleaguered offensive line to have someone who had started 22 games in his college career and could play either tackle or guard.

The Cardinal had just such a player, but he left with a year of eligibility remaining.

In fact, they’ll play against him Thursday night when they visit Arizona State.

Ex-Cardinal offensive lineman Casey Tucker has started five of the Sun Devils’ six games, three at left tackle and two at left guard. He missed the Colorado game with an ankle injury.

He’s one of the most experienced players on the ASU team. At Stanford, he started all 14 games in the 2015 Rose Bowl season, helping Christian McCaffrey run for a then-school-record 2,019 yards. Tucker started eight games in 2016 before sustaining an injury that led him to redshirt in 2017.

According to Stanford head coach David Shaw, he knew when Tucker spent last season on the sidelines that he might head elsewhere for the 2018 season as a graduate transfer. Tucker is a native of Arizona; he was an elite recruit coming out of Hamilton High-Chandler.

“We had a job open at guard for Casey to compete” for, Shaw said. “He wanted to go compete at tackle. Arizona State is close to home. He wants to play tackle at this level. He wants to play tackle at the next level. I understood and completely supported him.”

Thursday’s game Who: Stanford (4-2, 2-1 Pac-12) at Arizona State (3-3, 1-2) When: 6 p.m. Where: Tempe, Ariz. TV/Radio: ESPN/1050

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Stanford has lost several graduate transfers since 2006, when the NCAA ruled that an athlete who had graduated but had remaining eligibility could move to a school without sitting out a season.

Brennan Scarlett, a defensive end who had graduated from Cal, played for Stanford in that 2015 Rose Bowl season. Most of the time, graduate transfers are leaving Stanford, not coming to it.

Nevertheless, Shaw is a staunch supporter of the rule. “If a young man is at your place for four years and graduates and has a year left to play, and you don’t have a spot for him or he’s going to be a backup, I think he should be able to go anywhere in the nation to have a chance to compete,” he said.

Tucker has helped make a big difference in ASU’s offensive-line play. Tailback Eno Benjamin is sixth in the nation in rushing yards per game with 119.2. Last year, the Sun Devils were vulnerable to the sack, 120th in the nation in that department (3.15 per game); this year, they are 20th (1.17).

“There’s no certainty of what’s the best move overall,” Tucker told the Arizona Republic in July. “I really thought this was the best move, all things considered. I don’t want to go too far into detail. I still have a great relationship with that whole (Stanford) staff and everybody there. I’m actually really happy it ended up that way.”

Playing against his former teammates will be “a little weird,” he said. It’ll be a lot of fun, too.”

The 6-foot-6, 315-pounder has declined recent interview requests, possibly not wanting to draw attention to himself, especially because his former line mates have struggled.

Both starting tackles, Walker Little and A.T. Hall, have been hampered by injuries this year. Stanford ranks 126th out of 129 Football Bowl Subdivision teams in rushing.

One former teammate, fifth-year center Jesse Burkett, didn’t want to discuss whether Tucker could have helped the Cardinal. “All I know is I miss the guy a lot,” he said. “He’s a great friend. He’s a great player.”

Tucker didn’t take part in ASU’s spring practices because he hadn’t formally gotten his degree in philosophy yet. But first-year head coach Herm Edwards told him before the first spring practice that a starting spot was waiting for him.

Tucker has been feeding ASU offensive coordinator Rob Likens tips on the Stanford program. “It’s been great to just pick his brain and find out some of the things they do really well,” Likens told the Republic.

Tom FitzGerald is a San Francisco Chronicle staff writer. Email: tfitzgerald@sfchronicle.com Twitter: @tomgfitzgerald