Thomas became the second star player to go down in two weeks for the No. 9 Ducks during their 41-27 victory over No. 18 Arizona State. Thomas threw for 187 yards and two touchdowns before he came out with a left leg injury early in the second half.
"I'm going to be all right, just to let everybody know," he said, adding that he didn't return as a precaution.
James dislocated his elbow in Oregon's last outing, a 43-15 win over California on Oct. 6. Afterward, he greeted his fellow players outside the locker room, and told reporters it wasn't so bad.
In fact, James wouldn't rule himself out of the game against the Sun Devils, but when game time came Saturday he was on the sideline in sweats.
Brock Osweiler threw for 291 yards and two touchdowns for the Sun Devils (5-2, 3-1), who have lost seven straight to the Ducks.
It was Oregon's 20th straight victory at Autzen Stadium, as well as the Ducks' 15th straight win over a conference foe.
Without James, Oregon had a tough time getting its vaunted running game going against the Sun Devils, but the Ducks ended up with 327 yards rushing -- 269 in the second half.
"The bottom line is with Oregon, you're playing one of the best teams in the country, and if you allow them to run the football you've got problems," Arizona State coach Dennis Erickson said.
Bryan Bennett, who replaced Thomas at quarterback for the Ducks, completed two of five passes for 22 yards. He also ran for 65 yards.
"When one guy goes down the other guy feels like he's got to pick up the slack," Barner said. "That's what Bryan did and that's what I did."
On the first series of the game, Barner's fumble was recovered by the Sun Devils, who went on to take the early lead with Osweiler's 20-yard touchdown pass to Gerell Robinson.
Oregon tied it midway through the first quarter when De'Anthony Thomas ran a pitch from Darron Thomas 16 yards for a touchdown.
The Sun Devils went up 14-7 on Osweiler's 26-yard pass to Mike Willie. It looked as though Oregon had evened it again when Barner broke away with a 59-yard scoring run, but the TD was called back because of an illegal block.
The Ducks tied it at 14 on Darron Thomas' 28-yard touchdown pass to Lavasier Tuinei. The junior quarterback, who had just connected with Josh Huff on a 45-yard pass, was on the run and looked almost as if he were throwing the ball away -- but he caught Tuinei streaking across the back of the end zone.
Linebacker Shelly Lyons intercepted Thomas on the 41-yard line and ran it back to the Oregon 20, putting the Sun Devils in position to score again -- but they settled for Alex Garoutte's 47-yard field goal to pull back in front 17-14.
It was the 11th interception for Arizona State this season, surpassing last year's total.
Oregon answered when Cliff Harris, suspended to start the season after he was cited for speeding on a suspended license over the summer, intercepted Osweiler and ran it back 50 yards. The Ducks went on to score on Darron Thomas' 16-yard pass to David Paulson and take a 21-17 lead into halftime.
Arizona State regained the lead early in the second half on Cameron Marshall's 4-yard scoring run. But just a few plays later, Sun Devils linebacker Colin Parker fell on Thomas' legs, and the Oregon quarterback did not get up.
Darron Thomas grimaced as he was attended to by team trainers, but he got up and jogged off the field. He received further treatment on the sidelines before limping off to the locker room.
He was replaced by Bennett, who led the Ducks on a scoring drive that ended with De'Anthony Thomas' 3-yard touchdown run.
The Ducks extended their lead to 35-24 on Barner's 7-yard scoring run. Alejandro Maldonado had a 37-yard field goal early in the fourth quarter.
Garoutte added a 30-yard field goal for the Sun Devils, and Maldonado came back with a 24-yarder for the Ducks for the final margin.
After rushing for 23 yards in the first half, Barner got 148 in the second.
"I just had to let the game come to me rather than force it," he said.
Darron Thomas, who has thrown a touchdown pass in 19 straight games, eventually returned to the sidelines with a brace on his left leg. He watched with James, both players wearing dark green raincoats.
After the game, Thomas said both knees were hit.
"It didn't get twisted," he said. "I got landed on."
The Sun Devils have lost 16 straight games to teams ranked in the top 10.The announced crowd was 60,055, the largest ever at Autzen Stadium.