UCLA’s defense depleted by injuries, Arizona’s spread offense faces challenge

This game between top-20 teams already was intriguing even before it was riddled with question marks. UCLA will try to adjust after two more key injuries to its defense. Arizona may have a top player on its defense return to the lineup. Times staff writer Chris Foster examines the game’s matchups and story lines.

Depth perception

UCLA was already playing without defensive tackle Eddie Vanderdoes, who sustained a season-ending in the season opener. Then cornerback Fabian Moreau suffered a broken foot last week against Brigham Young. And Tuesday, during a non-contact seven-on-seven drill during practice, linebacker Myles Jack sustained a season-ending knee injury.

So the Bruins enter Pac-12 Conference play without three of their top defensive players.

Jack leaves a huge void. His speed and strength made him formidable against the pass and run. He also was a load to tackle when he was occasionally used as a running back. He debuted in the backfield at Arizona two years ago and gained 120 yards in six carries.

“I think the team has responded very well to some of the things that have happened this week that normally would be distractions,” UCLA Coach Jim Mora said.

Arizona Coach Rich Rodriguez has his own headaches.

All-American Linebacker Scooby Wright, the Pac-12’s defensive player of the year in 2014, is trying to come back from minor knee surgery. He practiced this week, but whether he is ready for game action is questionable.

The Wildcats may also be without two of their most productive receivers: Cayleb Jones (ankle) and Samajie Grant (ankle).

Historically speaking

Arizona rolled up some big numbers in a 77-13 win over Northern Arizona last week.

But Rodriguez’s spread offense has had difficulties against UCLA, and also against Tom Bradley, the Bruins’ first-year defensive coordinator.

UCLA smothered Rodriguez and the Wildcats, 66-10, in 2012 and 17-7 last season.

And when Rodriguez was coach at Michigan, he lost three times to Penn State, which had Bradley as defensive coordinator. The Wolverines averaged 19.0 points in those games.

Bradley sees this as a different situation.

“One thing is the personnel they have recruited,” he said. “They have had an opportunity to get guys in to fit their scheme. They are able to do it faster and do it better.”

UCLA’s defense was on the field for 40 minutes last week against Brigham Young. The offense needs to sustain drives that provide the unit a little in-game R&R.

Pass or fail

Anu Solomon, Arizona’s sophomore quarterback, would prefer to forget last season’s game against the Bruins. He threw 48 passes and only completed 18.

Through three games this season, he has 10 touchdown passes and has yet to have a pass intercepted.

Josh Rosen, UCLA’s freshman quarterback, has gone through growing pains since his magnificent debut against Virginia, when he passed for 351 yards and three touchdowns. He had three passes intercepted against BYU.

Desert run off

Arizona’s Nick Wilson is sixth in the nation with 434 yards rushing. That was built on the backs of games against Texas San Antonio, Nevada and Northern Arizona.

Wilson had 1,375 yards rushing last season.

UCLA’s Paul Perkins is a candidate for the best-kept secret in college football. He led the conference in rushing last season with 1,575 yards, but couldn’t make the All-Pac-12 team — first or second.

This season, running behind an experienced line, he is seventh nationally with 429 yards.

The Bruins are averaging 240.7 yards rushing and have not allowed a sack. With a depleted defense and freshman at quarterback, expect UCLA to keep running.

Site examination

Top-10 teams have struggled in Tucson since Rodriguez arrived. The Wildcats defeated No. 9 USC in 2012 and No. 5 Oregon in 2013.

UCLA has won 11 consecutive games away from the Rose Bowl.

chris.foster@latimes.com