Consensus All-American linebacker Rocky Calmus is gone from Sooner country. So is one of the hardest-hitting safeties ever to play for Oklahoma, Roy Williams.

But seven starters are back, and ISU head coach Dan McCarney said he thinks the Sooner defense has improved since last season’s team went 11-2 and advanced to the Cotton Bowl.

“There’s tremendous talent. They’ve got a great scheme and they play with as much relentless effort as anybody you’ll see in college football,” McCarney said. “They are just absolutely non-stop — they’re relentless and they’re tough.”

The Sooner defense, which ranks eighth nationally in scoring defense, allowing just under 15 points per game, specializes in shutting down the run. In six games, Oklahoma has held four teams under 100 yards rushing.

That includes then-No. 3 Texas last weekend.

Even with running back Cedric Benson, who averages 112 yards per game, the Longhorns were only able to generate 53 yards on the ground on 35 carries.

ISU receiver Lane Danielsen said the key to the Oklahoma defense is its speedy pursuit of the ball. He said the Sooners tackle as a team.

“You never see a play where, at the end of the play, they’re not all standing around the ball,” Danielsen said. “They fly to the ball, and they pursue great.”

Defensive tackle Tommie Harris leads the charge for Oklahoma. The 6-foot-3, 280-pounder has 14 quarterback hurries and two sacks this season.

Both sacks came against Texas as the Sooners came back to beat the Longhorns 35-24 last weekend.

Harris, a sophomore, is on the watch lists for the Lombardi Award and the Outland Trophy, which recognize the best lineman in college football. He was a first-team all-Big 12 pick last season.

“I have not seen a better defensive lineman in college football,” McCarney said.

“When you’re all-Big 12 as a true freshman, that says something — you’re a phenom, you’re in an absolute league by yourself. You can’t sit there and one-on-one block him all day; he’ll embarrass us.”

The challenge to hold back Harris lies squarely on the shoulders of ISU center Zach Butler and the rest of the Cyclone offensive line.

Butler said he’s seen the type of talent the Sooners boast before — in the first game of the season.

“We’re ready for it,” Butler said. “We’ve faced a Florida State team that is very similar in the way they play.”

He said the one of the Sooners’ best attributes is their ability to blitz — and blitz at the right time. All of Oklahoma’s linebackers tip the scales at more than 230 pounds, but Butler said it doesn’t slow them down one bit.

“All three of their linebackers are extremely fast,” he said.

Besides the run defense, Oklahoma will also try to shut down Seneca Wallace’s passing attack. The senior leads a Cyclone offense averaging 257 yards per game through the air.

McCarney said it will be tough to run the ball on the Sooners, but passing against them won’t be easy either.

“Their defense against the throwing game starts with the pressure up front and they do a great job of that,” McCarney said. “Their linebackers run like deep backs, much like Florida State.”

Butler said although Oklahoma is capable of shutting down high-powered offensive attacks, it’s not cause for a big change in the game plan.

“You’re not going to switch from your bread-and-butter plays,” Butler said.

“There’s going to be a couple new plays, but that’s every week. It comes down to your fundamentals.”