Lapses weaken once-dominant defense

After a dominating start, UCLA defensive coordinator DeWayne Walker’s unit has had consistency issues in recent weeks. From missed open-field tackles to blown coverages in the secondary, the Bruins’ defense has failed to get the job done at key moments during the team’s four-game losing streak.

“You don’t want to make excuses ... but you still have to tackle,” Walker said after UCLA gave up 433 yards to California in a 38-24 loss at Berkeley on Saturday. “It bothers me. It’s bothered me the last two games.

“We had games like this and then responded well. But now it’s happened back to back.”

Cal running back Marshawn Lynch and wide receiver/punt returner DeSean Jackson often danced around the first tackle attempt by the Bruins and then gained chunks of yards before being stopped.

The Bruins did not allow those types of plays early in the season. Back then, whenever a UCLA defender failed to make a tackle, a teammate would be close behind to make the stop.

Those types of hustle plays have not happened often enough lately.

“When you put guys in position, you want to see guys make the play,” Walker said. “That’s something that I really want to pay attention to.

“I don’t know if it is fatigue or what we concentrate in practice over and over again. Those are some good questions. And those are the things we need to really address as a coaching staff to get it fixed.”

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Although UCLA’s third quarter woes continued against Cal, the Bruins had a solid drive to start the second half, although it ended with a missed field goal. It was their best third quarter drive in weeks

“In general, our offense was a lot better this week and a lot better in the third quarter,” UCLA offensive tackle Noah Sutherland said. “We just left some more points out on the field.”

Senior Justin Medlock missed two field goals, including a 44-yard attempt in the third quarter that would have cut Cal’s lead to 14-13.

“We need to convert when we get those opportunities,” Sutherland said. “I don’t know if we’re trying to be perfect too much or not, but we have to be sharp. Defenses come at us harder and we have to be ready to execute by being sharper.”

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Over the last month, Coach Karl Dorrell has become more involved in the Bruins’ play calling, working closely with offensive coordinator Jim Svoboda.

“I was just helping Jim,” Dorrell said about his input in UCLA’s 516-yard effort. “I was part of the process with the organization this week in getting the game plan together. I thought he [Svoboda] made tremendous progress this week.”

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UCLA, 4-5 overall and 2-4 in the Pacific 10 Conference, needs to win two more games to become bowl eligible. Oregon State, which has won four games in a row, lost to UCLA, 51-28, at the Rose Bowl last year.

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lonnie.white@latimes.com