EUGENE, Ore. >> The Oregon Ducks opened camp Monday and as expected, the lingering quarterback questions took center stage.

Freshman Marcus Mariota and sophomore Bryan Bennett have 22 practices over the next three weeks to win the starting job for the Ducks’ season opener against Arkansas State on Sept. 1.

It’s a battle that began during the spring and carried over through voluntary workouts this summer.

“It’s a very exciting day to start another season with the Ducks,” said Bennett, the more experienced of the two quarterbacks after starting one game last season, a 45-2 win at Colorado, and playing in eight.

Coming off a 12-2 season that ended with a Rose Bowl victory against Wisconsin, expectations are as high as they have ever been for Oregon, the three-time Pac-12 champions.

All eyes are on the two quarterbacks in line to replace Darron Thomas, who was 23-3 as a starter, with 5,910 career yards passing, 66 touchdowns and 17 interceptions before leaving early for the NFL draft.

“I have a lot of faith in both those guys’ abilities,” coach Chip Kelly said of Bennett and Mariota. “Sam Rutigliano, the longtime NFL coach of the Cleveland Browns use to say, ‘It’s like a teabag, you don’t know what you’ve got until you put it in hot water.’ I anticipate them being very successful, but we’ll see. That’s obviously a big question for all of us.”

Bennett played well when called upon last season, throwing for 369 yards and six touchdowns and no interceptions on 25 of 46 passing. The 6-foot-3, 204-pound speedster from Encino, Calif., also ran for 200 yards on 23 carries.

Mariota, however, was the star of the spring game back in April, throwing for 202 yards and a TD, rushing for 99 yards and two scores and leading his team to a 41-14 victory. One of his TDs came on an 82-yard run.

Meanwhile, Bennett struggled, completing 59 percent of his passes for 209 yards one TD and two interceptions.

Both of those performances have added intrigue to the position battle this month.

“It’s an exciting time for us as a team,” said Mariota, a 6-4, 211-pounder from Honolulu. “This competition will get us better.”

Kelly said Monday he isn’t opposed to playing both quarterbacks this season, but doesn’t anticipate that will be the case.

“Everywhere I’ve been it’s always shaken itself out that one kid has emerged,” Kelly said.

Besides finding a new quarterback, the Ducks also have to replace the most prolific running back in school history in the incomparable LaMichael James, who also left for the NFL after his junior season.

James’ close friend Kenjon Barner will finally get his shot to be the primary running back after backing up James the last three seasons.

The senior has rushed for 1,856 yards and 20 TDs in his career, including 939 yards and 11 TDs last season on 152 carries.

“I’ve just been patient, waiting, and now that it’s here, I’m ready to take advantage of it,” Barner said.

Also back is sophomore De’Anthony Thomas, whose dynamic freshman campaign included 595 yards rushing, 605 yards receiving, 2,235 all-purpose yards and 18 TDs overall.

“I’m a lot more confident in myself right now,” Thomas said. “I believe I have a lot more in me.”

Thomas played a hybrid offensive role last season, regularly moving from running back to slot receiver. But the Ducks have depth issues at running back this season with Barner, Thomas and highly touted incoming freshman Byron Marshall the only players at that position on scholarship.

Thomas is currently the No. 2 running back and should expect to see an increased workload out of the backfield.

“The touches will be determined by the depth,” Kelly said. “There may be a game where he has to carry it 30 times because Kenjon’s not available. We’ll see how it goes.”

Kelly said Oregon has 105 players in camp this month, with only tight end Colt Lyerla, a projected starter, not available on Monday.

“Colt Lyerla, who had a great summer for us, has got a couple of things he’s got to take care of and should be at practice shortly,” said Kelly, who wasn’t any more specific when pressed on the matter.”