When Oklahoma starts preseason practice Thursday, most of the attention will be focused on the offense.

That’s not surprising since the development of a relatively young offensive line and the improvement of sophomore quarterback Rhett Bomar are two of the biggest questions surrounding the Sooners.

This also will be offensive coordinator Kevin Wilson’s first preseason with the reins all to himself and running back Adrian Peterson will be trying to return to his freshman form after an injury-plagued sophomore season.

All are important plot lines to how OU’s season will unfold. That’s why most will be focused on the offensive side of the ball.

But there’s another reason the Sooner defense could go a little unnoticed in the preseason.

There’s no debate OU’s defense will be good. The question is how good?

Many were comparing it to some of the best in Sooner history at Big 12 Media Days.

OU coach Bob Stoops wasn’t ready to throw around comparisons.

“Not yet, since I haven’t been on the field with them,” Stoops said. “Spring ball was a long time ago, and to me the most important time is what we do when we get back to work here.”

But Stoops wasn’t coy about the high expectations. He believes they’re warranted.

“Defense always begins with the guys up front, and we have a chance to be really good in our front four,” Stoops said. “And we have depth.

“Then the linebacker position, we have a couple of seniors (Rufus Alexander and Zach Latimer) that play awfully well. And then I think the biggest jump we can make from a year ago is our secondary that was awfully young and inexperienced as we started the year, finished playing awfully good through the season. And, really, I saw great improvement through the spring that we have a chance to be really good.”

The Sooners will open practice with eight starters back from last season’s defense and will be bolstered by the return of defensive end Larry Birdine, who missed last season with a biceps injury.

It’s a group that got better as last season went on and carried over into spring practice, dominating the offense throughout March and April. Most believe it will do the same when the season begins Sept. 2 when Alabama-Birmingham visits Owen Field.

Alexander, the preseason Big 12 defensive player of the year, is a big reason for the accolades. He’s a candidate for the Butkus and Bednarik Awards.