Stop Signs

There were times last season when it seemed as if UCLA’s defense never left the field. Giving up 296 first downs and an average of 34.2 points -- the most in the Pacific 10 Conference -- with 25 touchdown drives of nine plays or more can leave that impression.

And can cost a coach his job.

Coach Karl Dorrell kept his, but he made a change at defensive coordinator, replacing Larry Kerr with DeWayne Walker.

The change was welcomed by UCLA players eager to display their new coach’s pro-style system. Built around quickness, Walker’s defense makes its debut in Saturday’s season opener against Utah at the Rose Bowl.

“It’s really a fun defense to play in,” said junior tackle Kevin Brown, who sat out last season because of an ankle injury. “We have a lot of guys moving around, flying around. They want all-out effort, and when you get tired ... someone else will come in.

“We’re so comfortable in knowing that we have guys who can step in and play. Our D-line and linebackers can get breathers and we don’t have any drop-off. That’s been a problem for us in the past.”

UCLA’s defense ended last season on a slide, giving up 191 points in the last four games, but Walker saw some positives.

Shortly after he was hired, Walker pulled out UCLA’s game films from the 2005 season. He was looking for two things: effort and playmaking ability.

What he got was a surprise.

“Before I got here, all I heard was how [poor] the D-line position was,” said Walker, who was hired away from the Washington Redskins, for whom he coached defensive backs. “But what I saw was a group of bodies with potential.”

In Walker’s 4-3 scheme -- which features blitzes from all angles -- every defender has to be a strong tackler.

“I always tell guys that if they don’t score, they don’t win,” Walker said of his philosophy. “We’re going to have to be aggressive and we’re not going to sit on our heels.”

To help free the Bruins’ undersized but mobile linemen, Walker will often attack with hard rushes from linebackers or defensive backs.

“He’s brought a new attitude to the defense,” senior defensive end Justin Hickman said about Walker. “We just have to be consistent with our effort and doing what we’re told. We want to be able to dominate the whole game this year. We don’t want to just play well for stretches, like we did last season. We need to get it done from the start of games.”

Offense wasn’t a problem last season -- UCLA averaged 39 points a game, fifth in the nation. But the Bruins will be without the quarterback (Drew Olson), top rusher (Maurice Jones-Drew) and receiver (Marcedes Lewis) from that unit, making it imperative that the defense improve.

Ben Olson (no relation to Drew) is the new quarterback, and he comes with sterling credentials -- and possibly a little rust. The 6-foot-5, 227-pound left-hander was considered the top high school recruit in the nation in 2001, but he redshirted at Brigham Young and then went on a missionary assignment. He hasn’t played in a meaningful game since his senior season at Thousand Oaks High.

Chris Markey and Kahlil Bell will step in at running back. They combined for 297 yards rushing and two touchdowns in UCLA’s victory over Northwestern in last year’s Sun Bowl.

At tight end, sophomores Logan Paulsen and Ryan Moya, along with senior J.J. Hair, will do what they can to replace Lewis as the possession receiver.

Back on defense, first-year defensive line coach Todd Howard expects to use an eight-man rotation up front. Bruce Davis and Hickman will start at ends, backed up by Nikola Dragovic and William Snead. Brigham Harwell, Kenneth Lombard, Chase Moline and Brown will share time at tackle.

“I’ve been coaching technique, I’ve been coaching fundamentals and I’ve been coaching effort,” said Howard, who joined the Bruins from the NFL’s Jacksonville Jaguars. “They all know that we want all-out maximum effort on every play or they won’t be out there.”

At middle linebacker, junior Christian Taylor will rarely leave the field. He will call the defensive signals and be included in many of UCLA’s pass-coverage schemes.

“He’ll play an important role for us; he’s the quarterback of our defense,” Dorrell said about Taylor, a transfer from Air Force who played well in a reserve role last season.

With sophomore John Hale suspended for the season opener, junior Aaron Whittington and redshirt freshman Reggie Carter will open as the starting outside linebackers flanking Taylor.

Whittington replaced senior Eric McNeal with the first unit early in camp and has been impressive. Carter, who arrived from Crenshaw High as a middle linebacker, is one of the best hitters on the team and has made a smooth transition to the outside.

Safeties Chris Horton and Dennis Keyes will be relied on for support against the run while also being active in Walker’s blitz packages.

“I think they understand the chemistry and the formula,” Walker said. “We just have to go out and execute.”

UCLA’s cornerbacks -- starters Trey Brown and Rodney Van, along with backups Michael Norris, Alterraun Verner and Jeremy McGee -- will be asked to play more man coverage with the Bruins blitzing more.

A former standout college cornerback at Minnesota, Walker places a lot of responsibility on his defensive backs. “If there’s one thing that’s been different is that we’ve really concentrated on preparation,” said Trey Brown, a junior three-year starter. “A lot of film studying and individual work. Anything to make you a better prepared player on the field.”

With a group of quality backups -- including linebackers Shawn Oatis, McNeal and the Bosworth twins, Korey and Kyle -- the Bruins seem equipped to turn things around on defense under Walker.

“My whole thing is whether we can match what we do in practice on game days,” the coach said. “I’ve seen us do it in practice, but we have to get it done in a game. That’s our final exam.”

lonnie.white@latimes.com