CALIFORNIA (3-1, 1-0) at No. 19 USC (4-1, 2-0)

* Kickoff: 3:30 p.m. Saturday, Fox Sports West 2.

* Story line: USC is off to one of its best starts of the 1990s, but there are plenty of offensive problems to iron out before the Trojans hit a five-game stretch run that includes three games against top 25 teams.

* USC update: The Mike Van Raaphorst-Carson Palmer quarterback drama continues, and the Trojans keep overcoming offensive shortcomings with big plays, special teams and defense. Tailback Chad Morton’s back injury is a serious concern, and with him likely to miss a second game, either Petros Papadakis or Frank Strong needs to pick up the pace.

* Cal update: Despite a struggling offense that is scoring fewer than 14 points a game, the Bears are 3-1 because of an improved defense. The only loss is to No. 2 Nebraska, 24-3, with victories over Houston, Oklahoma and Washington State. The Bears’ defense is anchored by a strong front seven, and the hiring of former Arizona State defensive coordinator Lyle Setencich before last season is paying dividends.

* Edge to USC: A 5-1 record seems within easy reach, but the Trojans need to make some real progress offensively and reduce penalties.

* Line: USC by 12.