Surgery ends the season for Gable

Joe McKnight, Allen Bradford, Hershel Dennis and Desmond Reed found themselves in a relatively unfamiliar situation Wednesday.

The four USC tailbacks, relegated to minor backfield roles through the first four games, were competing for significant playing time in Saturday’s Pacific 10 Conference game against Stanford.

With sophomore Stafon Johnson almost certainly out because of a foot bruise and C.J. Gable opting Wednesday for season-ending abdominal surgery, the coaching staff is searching for starter Chauncey Washington’s running mate.

“We’re not going to give it to Chauncey 42 times this week, “ offensive coordinator Steve Sarkisian said.

McKnight, Bradford, Dennis and Reed all will play against the Cardinal, but only one is expected to get significant carries.

“They understand there’s a piece of the pie out there and they want to go out and get it,” Sarkisian said.

McKnight, the speedy freshman from Louisiana, appears to be a prime candidate to step into Johnson’s role. Although he has only 14 carries for 79 yards, coaches have emphasized for weeks their desire to work him into the game plan.

Last week against Washington, McKnight did not carry the ball. He lined up for one play as a receiver, but quarterback John David Booty’s pass fell incomplete.

“I wasn’t frustrated,” McKnight said this week. “We won the game, that’s all that matters.”

Bradford said he was ready to step up if given the chance. The sophomore from Colton is eager for the same opportunity that fellow sophomores Johnson and Gable received.

“If it’s my turn, I’m going to take it and run with it,” Bradford said.

Dennis, a sixth-year senior, carried four times for 14 yards against Washington State in his first game action since 2004. He did not carry the ball against Washington.

“Before I wasn’t really feeling like myself, but this week I feel great,” said Dennis, who has come back from two major knee surgeries.

Reed, a fifth-year senior, has played mainly in third-down situations and could expand on that role against the Cardinal.

Meanwhile, Gable chose not to put off surgery for a condition known as a “sports hernia” that has bothered him since last season. He will petition for a medical redshirt.

Gable was averaging a team-best 11 yards a carry, but his role had diminished since starting the opener against Idaho. He was held out of the Washington game so he would not lose a year of eligibility and was examined Tuesday by doctors.

Gable said the decision to have surgery now, rather than waiting until season’s end, was difficult. But he said, “I didn’t want to keep on going and make it worse.”

Coach Pete Carroll described Gable as, “a warrior” and said opting for surgery was “the sensible, right thing to do.”

“It all comes down to: He needs to get fixed up. He’s not right,” Carroll said. “He’s done everything, admirably, he can possibly do. . . . It won’t go away.”

Carroll said it would probably take Gable about eight weeks to recover and that he would be ready for spring practice.

Cornerback Cary Harris practiced but has not yet been cleared to play Saturday, Carroll said. Mozique McCurtis spent much of practice icing his left knee, but the senior remains on track to start at cornerback. . . . Former UCLA basketball coach Steve Lavin attended practice.

gary.klein@latimes.com