EUGENE, Ore. -- Oregon running back De'Anthony Thomas was honest. Yes, he did hurt his right ankle on the opening kickoff against California.

While second-ranked Oregon's coaches never talk about injuries as a strict policy, Thomas was frank about his situation even though he didn't have an exact diagnosis. All he knew for certain was that it hurt enough that he couldn't return against the Golden Bears.

De'Anthony Thomas has 485 all-purpose yards through
Oregon's first three games.
Mark J. Rebilas / USA TODAY Sports Images

As for this week's game at Colorado, Thomas would only say, ''We'll see.''

Thomas was injured on the opening kickoff of second-ranked Oregon's 55-16 victory against California on Saturday night. The turf was slick from a driving rain and he slipped.

He clutched his lower right leg before he was helped off the field. After the half, he appeared on the sidelines with crutches.

He was walking on his own following the game when he spoke to reporters.

''I was just trying to make a move and it was slippery out there,'' he said.

Thomas leads the second-ranked Ducks with 338 yards rushing and six touchdowns. He has 485 all-purpose yards through Oregon's first three games.

The 5-foot-9, 170-pound junior is known for confounding defenses with both his versatility and lightning speed. He also runs track at Oregon.

Last season he ran for 701 yards and 11 touchdowns and caught 45 passes for 445 yards and five more scores. He scored on a kickoff return and a punt return. He was the first Oregon player in 47 years with a touchdown four different ways.

In last season's 35-17 Fiesta Bowl victory against Kansas State, Thomas scored on a 94-yard return of the opening kickoff, the longest ever in an Oregon bowl appearance. In two career bowl games, he has amassed 509 all-purpose yards.

There were questions in fall camp about whether Thomas would be used more as a running back or a receiver, since he is adept at both. For Oregon's 59-14 victory against Tennessee on Sept. 14, he started at receiver, but for the Cal game he was slotted at running back.

Thomas was scheduled to have X-rays on the ankle Sunday, but he was confident when he spoke after the game that it was not serious.

''I'm very focused and I'll get back out there when I can,'' he said.

Early Sunday Thomas posted to Twitter that Cal ''got lucky'' he didn't play.

Thomas' absence against the Golden Bears paved the way for sophomore backup Byron Marshall to run for a career-high 130 yards and two touchdowns.

''We knew we were going to have to run more than normal with 100 percent chance of rain,'' Marshall said. ''The coaches adjusted on the fly a little bit and we had to take what the defense was giving us and what the weather was giving us and just go from there.''

Head coach Mark Helfrich said Marshall, like several of the other Ducks in the soggy conditions, needed to work on protecting the ball. Marshall fumbled the ball three times, but Oregon recovered all of them.

Of Oregon's six fumbles, two were lost. When Cal's Jalen Jefferson scooped up a fumble in the first quarter, it was Oregon's first turnover of the season and the team's first lost fumble in eight games.

''Definitely, he needs to control the ball a little bit better there a couple times and like I said, we got a little lucky a couple times there,'' Helfrich said. ''We have a ton of confidence in Byron, he had an exceptional fall camp there and needs to keep developing.''