Top-ranked Arizona will be without starting forward Brandon Ashley for the remainder of the season with a foot injury.
Ashley, who was averaging 11.5 points and 5.8 rebounds per game, suffered the injury three minutes into Saturday night's loss to California when he landed awkwardly after rebounding his own missed shot. He returned to the bench and was in a walking boot and on crutches in the second half.
"Last night, early in our Cal game, Brandon Ashley suffered a foot injury that will end his season," Arizona coach Sean Miller said in a statement. "While we're all disappointed, we are also aware that Brandon needs our support and positive energy surrounding him. ... This adversity will ultimately make Brandon and our team stronger moving forward."
Miller feared the injury was a broken foot after the game.
"We have to get back to the drawing board and make sure we can move forward if Brandon is not with us," Miller said shortly after the loss.
The 6-foot-8, 230-pound sophomore, a former McDonald's All-American, had been a key to Arizona's success. The Wildcats were unbeaten, winning 21 consecutive games prior to the setback against the Bears.
Ashley will be replaced in the starting lineup by talented freshman Rondae Hollis-Jefferson, but the loss of Ashley will alter Sean Miller's rotation.
Hollis-Jefferson had quickly established himself as one of the top reserves in the country, and Miller told ESPN.com that seldom-used big man Matt Korcheck will likely receive more playing time. The 6-foot-10 Korcheck, a Tucson native, played just one minute against Cal after not playing in the previous three contests.
Arizona is expected to fall out of the No. 1 spot when the new polls are released on Monday. The Wildcats will play Oregon in Tucson on Thursday night.