The Oregon Ducks' 10-2 run since the start of February handed them the No. 1 seed in the Pac-12 tournament.
Oregon earned the top honors despite losing to the second-seeded USC Trojans by 14 points on February 22.
For the Ducks and Trojans to meet again, they need to win two games each at T-Mobile Arena on Thursday and Friday.
The competition begins with three first-round games on Wednesday, but unlike the other power conferences, they will not involve teams fighting for their NCAA men's basketball tournament lives.
Only four Pac- 12 programs are projected to qualify for the field of 68, and if one of the other seven squads wins in Las Vegas, it would be viewed as a massive shock.