Fifth-ranked USC plays its first road game of the season against California in Berkeley on Saturday night in a game between 3-0 teams that don't yet know how good they are.

The Trojans were impressive in their 42-24 victory over Stanford, but their other two games against unranked foes were less awe-inspiring. They were tied with Western Michigan midway through the fourth quarter before pulling that one out, and they trailed Texas with just 45 seconds left in the fourth quarter before winning in double overtime.

"That's the best two-minute drive I've ever been associated with," USC coach Clay Helton said after the game.

The game-tying drive might have been a thing of beauty, but Helton later added: "Ugly wins count too."

Another issue is the rash of injuries on the Trojans' defense. Defensive end Rasheem Green (high ankle sprain), outside linebacker Porter Gustin (toe, shoulder), defensive tackle Marlon Tuipulotu (knee) and linebacker John Houston Jr. (neck stinger) missed all or part of the Texas game and are questionable for this week.

Although quarterback Sam Darnold demonstrated his ability to make big plays when USC needed them most, the Trojans have not been nearly as dominant as expected. And all three games were at home at the Los Angeles Coliseum.

This week the Trojans have to travel to Berkeley to take on a Cal team that has exceeded expectations so far and will be excited to face one of its chief rivals in its conference opener.

The Bears pulled off a road win against a pretty good North Carolina team in their opener, then, after struggling more than they should against Weber State, made a statement with a 27-16 home win over Mississippi on Saturday.

First-year head coach Justin Wilcox, who was the defensive coordinator at Wisconsin last year, seems to have transformed a Cal team that had little defensive initiative under previous head coach Sonny Dykes into a defensive force.

Inside linebacker Devante Downs, who leads the Pac-12 in tackles, had 14 tackles, two sacks and an interception as the Bears shut out Ole Miss in the second half and held the Rebels to fewer than 100 yards after halftime.

"Justin is a brilliant defensive-minded coach," Helton said. "You see a team that is playing with great confidence."

The Bears are 3-0 for the first time in six years.

"We set pretty high standards," Wilcox said. "We feel we can play a lot better and need to play a lot better."

There is certainly familiarity among the coaches as Wilcox was USC's defensive coordinator in 2014 and 2015. Helton was the Trojans' offensive coordinator those two seasons and was interim head coach for much of the 2015 season. It may not mean much during Saturday's game, though.

"I don't think there's any intimate knowledge that gives you an edge," Wilcox said.

Questions regarding Cal's defense remain. Although Cal has significantly reduced the points it has allowed from 42.6 last season to 22.0 through three games this season, Cal still ranks 114th of 129 FBS schools in total defense this week and has not faced a ranked team.

"Seeing how we're not ranked, we need to get respect," Downs said.

Although there may be questions about how good these teams are this season, there is no uncertainty about which team has had the upper hand in this series. USC has beaten Cal 13 times in a row. The last time Cal beat the Trojans, in 2003, Aaron Rodgers was Cal's starting quarterback, and it still took three overtimes to finish it off.

Cal does not have someone like Rodgers on its roster this year. Bears quarterback Ross Bowers has been good, not great, completing 60.2 percent of his passes with five touchdowns and four interceptions. Darnold, meanwhile, has completed 66.7 percent of his passes with seven touchdowns, although his six picks are a bit troubling.

USC running back Ronald Jones II is averaging 107.3 yards per game, and his sidekick, freshman Stephen Carr, has rushed for 72.0 yards per game. But they combined for just 75 yards against Texas.

Patrick Laird leads Cal in rushing, averaging 92.7 yards per game and 7.5 yards per attempt.

USC's big-play man is wide receiver Deontay Burnett, who has 24 catches for 386 yards and four TDs.

Meanwhile, Cal's top receiving threat, Demetris Robertson, is a mystery. He sat out the Mississippi game with an unspecified injury, and the Bears do not plan to update his status until Saturday.

Robertson had seven catches for 70 yards and two carries for 40 yards and a touchdown in Cal's first two games. He had 57 receptions for 837 yards and seven touchdowns last season as a freshman.