Norman, Okla. ? Working to shore up an offensive line that failed to free up Adrian Peterson, Oklahoma got much younger and a whole lot bigger up front.

The 21st-ranked Sooners are turning to mammoth freshman tackles Branndon Braxton and George “Duke” Robinson to provide a lift – or perhaps a push – for the offensive line.

At 360 pounds, Robinson is the most massive player on the Sooners’ roster. The 6-foot-5 Atlanta native is 42 pounds heavier than Braxton, who’s the second biggest offensive lineman and stands 6-foot-6.

With the two inserted into the lineup, the Sooners (1-1) mauled Tulsa for 227 rushing yards, including 180 by Peterson in the second half last week. After being held to 97 yards rushing in an upset loss to TCU in Week 1, the offensive front was able to regain some confidence while the Sooners went without a pass attempt in the second half.

“We’ve got the attitude back that we needed,” offensive line coach Kevin Wilson said, “but that attitude is not going to line up and run against 10 guys in the box every game.”

The next step for the linemen is to prove themselves in the passing game – something that’s been almost nonexistent for Oklahoma so far this season.

“That’ll probably be the hardest thing to get used to coming from the high school level. The pass rushers are a lot faster,” said Braxton, who signed with Oklahoma prior to last season but qualified late and didn’t enroll until this spring.

“Pretty much, run blocking is a lot of effort. Getting off real fast and knowing your assignment. Pass blocking is a lot harder. You’ve got to have good technique.”

The Sooners have accelerated the development of Robinson and Braxton after a flurry of departures at the tackle position. Last year’s starters, Jammal Brown and Wes Sims, were both drafted into the NFL and one of this year’s projected starters, Akim Millington, left the team and returned, only to leave again. Brandon Keith, a junior college transfer who figured to contribute, also left the team.

That means Robinson and Braxton must learn quickly.

“It’s more than just knowing what to do, but how to do it,” said junior Chris Chester, a converted tight end who has shifted to guard and now to center. “That kind of comes from game experience and experience in practice.”

So far, the Sooners have been pleased with the development of the two young tackles. Coach Bob Stoops said both were cited in team meetings as having strong games.

“They’re still learning and improving as they go, but they played with some attitude and toughness that we needed,” Stoops said. “I believe we’ll build off of that.”

The first big test of the duo’s pass blocking abilities will likely come today against UCLA. Oklahoma coaches say they don’t expect they’ll be able to scrap the pass against the Bruins (2-0) as they did against Tulsa.

To make the transition easier, Wilson said the Sooners will consider using different protection schemes and timing plays that may be less demanding for the young tackles, and also choose carefully the times they leave the youngsters out on an island blocking by themselves.

“Those two big guys do have a lot of size, a lot of athleticism and a lot of potential,” he said. “There’s going to be some growing pains. We’ve got to make sure we’re doing some things that can help them as we open the offense back up and throw the ball.”