Colorado’s Jabari Walker, right, and Southern California’s Isaiah Mobley go after a loose ball during the second half of an NCAA college basketball game Thursday, Dec. 31, 2020, in Los Angeles. Colorado won 72-62. (AP Photo/Jae C. Hong)

Things to watch this week in Pac-12 Conference basketball:

GAME OF THE WEEK: No. 19 Southern California at Colorado, Thursday. The Pac-12 race got a little tighter following the Trojans’ home loss to Arizona last Saturday. USC leads the conference race at 13-3, but is just a half-game ahead of rival UCLA (12-3). The Buffaloes are fourth at 11-6 and are coming off a split with the Oregon schools. Colorado won the first meeting against USC 72-62 at the Galen Center on Dec. 31 and has won five straight in the series.

LOOKING AHEAD: UCLA plays Colorado on Saturday, two days after playing at Utah as the season winds down to its final two weeks. … Oregon had been on a roll, winning five straight before losing to USC on Monday. The Ducks, third in the Pac-12 at 9-4, play at the Bay Area schools, then have a rescheduled game against Arizona on Monday. Oregon has won six straight in that series. … The Washington schools are in the desert this week to face Arizona and Arizona State.

INSIDE THE NUMBERS: The Pac-12 adjusted the conference tournament bracket, giving the top five teams an opening-round bye instead of the top four. The tournament will have 11 teams after Arizona self-imposed a postseason ban. The tournament runs March 10-13 in Las Vegas. … Arizona’s Azoulas Tubelis was named the Pac-12 freshman of the week after averaging 17 points and 11.5 rebounds in games against USC and UCLA.

PLAYER TO WATCH: Noah Williams, Washington State. The sophomore guard had himself quite a week. Williams had 32 points in a win over California and followed that with 40 points in a triple-overtime win over Stanford to help the Cougars sweep the Bay Area schools for the first time since 2011-12. He was named national and Pac-12 player of the week.

ON THE WOMEN’S SIDE: Stanford moved up to No. 4 in this week’s poll and clinched its first regular-season title since 2014 with a 62-48 win over No. 9 Arizona on Monday. The Cardinal host rival Cal on Sunday. … Arizona and Arizona State resume their rivalry on Sunday. The Wildcats won the first meeting 65-27 on Dec. 10. … No. 10 UCLA and USC also have a rivalry rematch on Friday. The Bruins won the first meeting 73-52 on Dec. 13.

Compiled by AP Basketball Writer John Marshall in Phoenix.