Oklahoma coach Bob Stoops said Monday Adrian Peterson’s availability for Saturday’s Big 12 championship game “unlikely.”

Tuesday, he ruled it out altogether.

“Adrian is not going to play,” he said Tuesday at his weekly news conference. “Without being too technical, he’s close. He could be cleared to play, but each week that passes the likelihood of it reoccurring is less and less.”

Peterson, who rushed for 935 yards in the first six games, has missed the last six with a broken collarbone. The eighth-ranked Sooners have won all six of those games and have continued to run the ball effectively with Allen Patrick and Chris Brown. They will handle the running back chores when the Sooners face No. 19 Nebraska at 7 p.m. Saturday at Arrowhead Stadium in Kansas City, Mo.

Stoops said the injury has healed well enough that Peterson could play. But the bone still isn’t 100 percent.

“There’s still a chance if he fell on it wrong or took a severe hit — I don’t know if they’re totally sure will it hold up at this point?” he said. “We’re not going to take that chance.”

Peterson, who set an NCAA freshman rushing record in 2004 with 1,925 rushing yards, is 150 yards shy of Billy Sims’ all-time OU rushing mark of 4,118 yards.

Stoops still believes Peterson will have a chance to eclipse the mark in a bowl game. The coach still believes the junior will play in the bowl game.

“The bowl game is a very likely possibility and very likely to happen,” he said. “Talking to Adrian, he absolutely wants to play. And by that time, that’s another four weeks of healing … and there is a really small chance of anything happening to it.”