UCLA must contain Cal’s diversified attack

If UCLA is to stretch its Pacific 10 Conference-leading winning streak to seven games, the Bruins’ defense will have to play lights-out football against California’s high-powered offense.

Of course, that’s a lot easier said than done.

Whether it’s returning starter Nate Longshore or backup Kevin Riley starting at quarterback, the Bears have one of the best balanced offenses in the league. That proved to be a dilemma for the Bruins last season when they lost at Cal, 38-24, and will be the main challenge they face Saturday at the Rose Bowl.

Starting with game-breaking wide receiver and kick returner DeSean Jackson and running back Justin Forsett, the Bears are loaded with talented and experienced playmakers.

When opponents try to take Jackson away from Cal’s passing game, fellow wide receivers Robert Jordan and Lavelle Hawkins are there to pick up the slack.

And when defenses load up on defensive backs to provide more pass coverage, Forsett is capable of pounding out yards on the ground.

It’s diversity that makes the Bears so difficult to defend and why they average 434.7 yards and 37.5 points a game.

Although DeWayne Walker, UCLA’s defensive coordinator, returned an experienced unit this season, the Bruins’ play -- from struggling to shed blocks to poor tackling -- has been spotty. But over the last three games, the Bruins have shown signs of growth, especially against the run.

Led by Bruce Davis and Kevin Brown, UCLA is giving up 81.7 yards per game on the ground -- third-best in the Pac-10 -- and that stinginess will be crucial against Cal, which is expected to give the Bruins a heavy dose of Forsett, the conference’s leading rusher.

The Bears have an offensive line that does a good job mixing traps and power blocks along with pass protection. Rarely do you see a defense jump a play because Cal tipped its hand.

But in last week’s upset loss to Oregon State, the Bears’ front labored to keep defenders from penetrating. The Beavers were able to pressure Riley and stop Forsett from scoring on a key goal-line situation in the second half.

UCLA needs similar play from its defensive line. Davis, Brown, Jess Ward, Brian Price and Co. can’t just be active -- they need to be aggressive enough to free up Christian Taylor and UCLA’s other linebackers.

As Oregon State’s Alan Darlin proved last week when he had 14 tackles, one sack and one forced and recovered fumble, versatile and athletic linebackers give the Bears problems.

UCLA’s defensive success is based on stopping teams on first down to help create third-and-long situations. That’s one reason why the Bruins lead the nation in third-down conversions allowed at 23.7%. But the Bears love to spread a defense with multiple receivers and run on first down. If UCLA is unable to slow this tactic, game over: Cal.

Summary: Jackson may be the headliner of Cal’s offense, but the Bears’ calling card is Forsett and their running game. UCLA’s defense misses injured defensive tackle Brigham Harwell but still has veterans such as Davis, Chris Horton, Dennis Keyes and the Browns (Kevin and Trey), who can get the job done.

If Walker can get production from his front four without needing to call too many aggressive blitzes, the Bruins will be able to match up better against Cal’s explosive offense than they have in years past.

lonnie.white@latimes.com