USC returns to the Galen Center this week after losing three straight on the road.
The Trojans surrendered a nine-point lead and lost by three on a last-minute three-point basket at UCLA, allowed Arizona State to go on a game-ending 9-0 run and win by two on a last-second shot, and could not keep pace at Arizona in a 14-point loss.
"We've been playing good basketball," coach Andy Enfield said after practice Wednesday. "But we have to defend at a high level like we're capable of."
USC (17-9, 8-5 Pac-12 Conference) will try to regroup against Oregon (17-8, 7-5) on Thursday.
"We've got to prepare better," senior guard Elijah Stewart said. "Get some extra shots up, get some extra defensive slides in and just hope for the best."
The Trojans lost 14 straight to the Ducks before a five-point victory in Eugene last month, but they have not defeated Oregon at home since 2009.
"Everybody they put on the floor can score," Enfield said. "We know we're going to have to challenge to try to hold home court."
Sophomore guard Derryck Thornton made his first start at Arizona in place of junior Shaqquan Aaron. Thornton finished with seven points and three assists. Enfield said he would make a game-time decision as to who would start against the Ducks.
USC had a six-game win streak, its longest in conference since 1992, before losing three straight.
A win over Arizona would have given the Trojans a share of the conference lead. Instead, USC sits two games behind Arizona and shares second place with UCLA — while being among four five-loss teams in the conference.
Five games remain before the conference tournament.
Stewart said that the team does not feel added pressure since falling into the thick of the standings, but understands that they must protect home court before making a trip next week to Colorado and Utah.
"We just have to get the job done," Stewart said. "We're a veteran group and we just have to stick together."
When: Thursday, 6 p.m., PST.
Where: Galen Center.
On the air: TV: ESPN2; Radio: 690.
Update: USC allowed Arizona to shoot 56% on Saturday in a ninth consecutive loss at the McKale Center. Oregon is coming off an 84-57 victory over Washington in Eugene. The Ducks have won five of their last six since losing to USC 75-70 on Jan. 18.