ARIZONA STATE (2-2, 1-1) at No. 21 USC (3-1, 1-0)

* Kickoff: 4 p.m., Channel 7.

* Story line: Which way will the season go? USC and Arizona State should get a hint whether it’s onward and upward in the Pacific 10 or a difficult road ahead. USC is also looking for payback after devastating defeats against the Sun Devils two years in a row.

* USC update: The offense won’t face the obstacles it did when the Trojans were held to 23 yards passing against Florida State. But Arizona State held USC to one touchdown last season in a 35-7 victory. Words of caution: Tailback Chad Morton and receiver R. Jay Soward aren’t at 100% because of nagging injuries.

* Arizona State update: The season will go from disappointment to full-fledged flop if the Sun Devils don’t recover from losses to Washington and Brigham Young and beat a ranked team after getting back to .500 against North Texas and Oregon State. Sophomore quarterback Ryan Kealy had a breakthrough game against USC as a freshman last season, and J.R. Redmond is an all-purpose threat as a running back, receiver, kick returner or defensive back.

* Edge to Arizona State: So the Sun Devils aren’t national title contenders. They’re still probably a notch above USC in the Pac-10.

* Line: USC by 3.