The circumstances that shifted Paul Thompson back to quarterback was the biggest story of Oklahoma’s preseason. But there’s another mystery that could have a bigger impact on the season.

The offensive line has the weight of the world on its broad shoulders. All the talent the Sooners possess at the skill positions can’t be unleashed unless there are holes to run through and time to throw the ball.

But the burden doesn’t seem to be causing any sleepless nights in the Sooner camp.

“It doesn’t worry me at all because I know the guys we’ve got,” sophomore center Jon Cooper said. “We have a lot of talent, a lot of young talent. They’re guys everybody doesn’t know about, but they will.”

It was no secret 2006 was going to be a rebuilding year for the unit. Four of OU’s five starters from last year’s Holiday Bowl team were seniors. Davin Joseph, Chris Chester, Chris Bush and Kelvin Chaisson started a good chunk of the games.

Only tackle Chris Messner is back from the unit that finished the season. Sophomore tackle Branndon Braxton started three games last season. Jon Cooper started two games late in the year, but also suffered a season-ending ankle injury.

New offensive line coach James Patton arrived after five seasons handling Northwestern’s offensive line. When he arrived in the spring, injuries and low numbers left the Sooners building nearly from scratch.

Messner, Braxton, sophomore guard Duke Robinson and junior college transfer Brandon Walker played virtually every snap in the spring. Cooper returned to the fold when preseason practice began.

But whatever didn’t kill them has made them stronger.

“The guys are working real hard. I challenge them every day to come out here with the right attitude,” Patton said. “That’s what blocking is. It is attitude and effort. If we have that then the schemes will obviously take care of themselves. We will know the schemes and we will learn them all, but what it comes down to is you wanting to block that guy in front of you or that guy you are supposed to block.”

Thus far, the unit has answered the coaching staff’s questions. In OU’s only open scrimmage, they only allowed one sack.

The group is versatile. Robinson has also worked at tackle and Messner has played at center.

But versatility is a necessity with this group.

With the exception Sherrone Moore, a junior guard, the rest of the backups are freshmen.

The coaching staff is enthused about the progression of Chase Beeler, who is the second team center, and Trent Williams, a tackle.