NORMAN, Okla. - UCLA visits Oklahoma on Saturday with an offense that ranks 117th nationally, dead last in Division I-A. If all goes as expected on Owen Field, the Bruins figure to occupy the cellar at least one more week.

EVER SINCE BOB STOOPS became Oklahoma’s coach in 1999, his defenses progressively have improved.

Obviously the defenses have been stout. The Sooners have won the national championship, the Cotton Bowl and the Rose Bowl the last three years.

Before last season, the Oklahoma defense adorned several preseason publications. One pictured frowning defensive tackle Tommie Harris and proclaimed the Sooners’ defense was “So Good It’s Scary.”

But from the outset, however, Oklahoma coaches cringed at the proclamation.

“We’re still a year away,” co-defensive coordinator Mike Stoops said on Kyle Field during pre-game warm-ups before the then-No.1 Sooners played at Texas A&M last season.

Five hours later, the Aggies had stunned Oklahoma with a 30-26 victory during which Texas A&M freshman quarterback Reggie McNeal passed for 191 yards. Four of his eight completions went for touchdowns. He also rushed for 89 yards.

Three weeks later, intrastate rival Oklahoma State also burned the Sooners deep, gaining 506 total yards (357 through the air) en route to a convincing 38-28 victory during which the Cowboys led 35-6 at one point.

Oklahoma went on to win the Big 12 championship, dominated Washington State in the Rose Bowl (34-14) and finished 12-2 overall. But Mike Stoops was right. There was a chink in the Sooners’ armor.

But next year is now.

In the 2003 opener against New Orleans Bowl champion North Texas, Oklahoma held the Mean Green to 50 total yards through three quarters.

At Alabama two weekends ago, Oklahoma had six sacks and two interceptions. The Crimson Tide managed 120 yards in the first half and 50 in the fourth quarter.

Last week against Fresno State, the Sooners jumped out to a 38-0 halftime lead with thorough domination. Before intermission, Oklahoma had outgained the Bulldogs 370-43 and led 23-2 in first downs.

“We seemed to be in the shadows of our goalposts every time we turned around,” Fresno State coach Pat Hill said.

“All the pieces came together,” Bob Stoops said.

On Saturday, UCLA’s struggling offense (223.5 yards) will try to right itself against a defensive unit that’s being mentioned among the best in the program’s storied history.

“That’s the best defense I’ve ever seen,” UCLA sophomore quarterback Drew Olson said after studying film of the Sooners earlier this week. “USC was good last year, but Oklahoma is awesome.”

The last time the Bruins played the top-ranked team was the season-opener in 1986. That team happened to be Oklahoma, which beat No. 4 UCLA, 38-3, on Owen Field in a game former All-American linebacker Brian Bosworth said the Bruins played “like girls.”

The Sooners have featured some prolific defenses through the years.

They led the nation in total defense three straight seasons in 1985-87. They led the nation in rushing defense five times, scoring defense four times and passing defense three times.

In terms of the complete package, however, most longtime Oklahoma observers agree defenses from the 1970s and mid-1980s were a tad more stout than the current unit — but not by much.

Ever the perfectionist, Bob Stoops calmly evaluates this defense with cautious optimism, his most common response being, “If we continue to improve, we have a chance to be pretty good.”

Oklahoma, which once again is atop the polls, returned 10 defensive starters from last year (including defensive back Antonio Perkins, who had seven starts).

Of that group, six were chosen for national watch lists for various national individual awards.

Five players were voted preseason All-Americans in senior linebackers Teddy Lehman and Lance Mitchell, senior defensive backs Brandon Everage and Derrick Strait and Harris, who is a junior. Junior Jonathan Jackson is a nominee for the Ted Hendricks Award as the nation’s top defensive end.

To shore up their lone weakness at strong safety, the Sooners recruited junior college transfer Donte Nicholson, who was a near-unanimous pick for Big 12 newcomer of the year.

“They’re so talented in every spot,” Olson said. “Their linebackers and linemen are athletic. Sometimes you can find weaknesses, but there are not too many in this defense.”

Had their reserves not played significantly in two of the first three games, the Sooners likely would lead the country this season in total defense (they rank ninth at 240.7 yards).

Oklahoma’s defense did suffer a blow against Fresno State last week when Mitchell was lost for the season with a torn anterior cruciate ligament in his left knee. He plans to apply for medical redshirt and return next season.

“We were playing as well as we ever have here,” Mike Stoops said of his defense. “We were playing probably the best defense of anybody.”

But so thick is the Sooners’ depth, even losing a player of Mitchell’s magnitude doesn’t figure to be disastrous.

Junior Gayron Allen, sophomores Wayne Chambers and Clint Ingram and true freshman Lewis Baker competed this week to fill Mitchell’s vacancy.

“We’ll still be really good,” co-defensive coordinator Brent Venables said. “Some guys have to step up, there’s no question about it. But we’ve got enough ability.”

Even without Mitchell, many believe this year’s defense is strong enough to carry the school to its eighth national title (all since 1950).

John Rohde is a contributor for NBCSports.com and a columnist for The Oklahoman in Oklahoma City at www.oklahoman.com