Oregon State tailback and Heisman Trophy candidate Stephen Jackson looks to duplicate the effort of California running back Adimchinobe Echemandu, when the Beavers (5-3, 2-2 Pac-10 Conference) play host to the struggling Arizona football team Saturday in Corvallis, Ore.

Echemandu ran for 201 yards and three scores on 30 carries against the Wildcats Saturday in Berkeley, Calif.

"We have to be ready to go out there and stop the run," said UA junior defensive end Copeland Bryan. "Last week we had a little bit of trouble against Cal."

Jackson currently sits fifth in the nation in rushing yards at 1011, on 233 carries. The junior has also rushed for nine touchdowns, and looks to extend that success against Arizona.

"We're trying to be a good defense overall, in every aspect," Bryan said. "The coaches have made a little bit more of an emphasis, saying (Jackson's) name, letting us know (he) is one of the better backs - if not the best back we've seen."

UA senior defensive back Clay Hardt added that the defensive coaching staff is placing special emphasis on run defense during practice this week.

"We have to stop the running game. Cal took the ball and just ran it down our throats," said Hardt. "If we don't stop the run game early, we're going to be in the same situation. We really have to concentrate on that this week."

Off-field troubles scratch Farmer from starting lineup

Going into the final stretch of his UA career, senior tailback Clarence Farmer's return to prominence hit another snag this weekend, just a game removed from a 25-carry, 122-yard effort at home against UCLA.

Farmer's on-field resurgence took a backseat this week to more off-field problems.

Farmer carried the ball just six times for the game and just once in the second half - a 1-yard pickup in the third quarter - good for just 21 yards.

Farmer's limited production was a product of a punishment handed down by the Arizona coaching staff. While Hankwitz wouldn't disclose the nature of the infraction, the first-year head coach did say that Farmer broke team rules earlier in the week, leading to the fourth-year back's minimal playing time.

"Clarence violated some team rules, so we told him he wasn't going to start," Hankwitz said. "He's got to abide by our team rules and he didn't."

With just four games left in his tumultuous UA career, Farmer is now seeing more competition than ever for a shot at handling the bulk of Arizona's rushing duties.

Sophomore running back Michael Bell solidified his spot in the UA backfield against UCLA and Cal, combining for 276 yards on 27 carries over the Wildcats' two losses. Bell also pulled in two catches for 22 yards over the stretch, and added a touchdown on the ground against the Golden Bears.

Bell's career high 182 yards on 18 carries - for an average of 9.6 yards - brings stability to an otherwise enigmatic UA running game this season.

Riley winless against Cats

OSU head coach Mike Riley, currently in his second stint at the helm of the Beavers, looks to change his fortune against Arizona this weekend.

After coaching the Beavers for two years from 1997-1998, Riley was coach of the NFL's San Diego Chargers for the past four seasons.

While OSU has won the past four meetings between the two schools, Riley lost his only two attempts at beating the Wildcats.