Try as he might, Oregon coach Dana Altman just can't understand why his team came out so flat with so much on the line.

After all, the 19th-ranked Ducks had a chance to take a big step toward winning an outright Pac-12 Conference title.

Now, they're hoping for a share of the championship after a humbling 76-53 loss to Colorado on Thursday night.

Oregon (23-7, 12-5) dropped into a first-place tie with UCLA, but the Ducks hold the tiebreaker after beating the Bruins in their only meeting in January.

Altman's team closes out the regular season at Utah on Saturday. A win would give the Ducks at least a share of their first league crown since 2002, along with the No. 1 seed for the Pac-12 tournament.

That's why they can't dwell on this defeat.

"This one is done and there's nothing we can do about it," Altman said. "I don't say that very often, but we definitely have to say it this time. It's over with; we have to bounce back real quick.

"We still have half a championship to play for."

The Ducks couldn't find any sort of offensive rhythm, shooting just 37.5 percent from the floor and going 9 of 22 from the free-throw line.

"We just played terrible tonight, bottom line," said E.J. Singler, who was held to just two points on 1-of-5 shooting.

The Buffaloes (20-9, 10-7) may have played their best game of the season, even without the nation's leading rebounder, Andre Roberson, who was sidelined with a viral illness.

Freshman Xavier Johnson stepped up in Roberson's absence, scoring a career-high 22 points on a nearly perfect night. Johnson hit all seven of his shots, including three 3-pointers. His only miss was a free throw, finishing 5 of 6 from the line.

"Trying step my game up with Andre out," Johnson said.

He was far from alone. After all, the Buffs were without Roberson's 11.5 rebounds and 10.8 points a game.

"We all just tried to pitch in," said Spencer Dinwiddie, who finished with 17 points. "When Andre goes out, we lose 11 points and 11 rebounds. We knew 11 points and 11 rebounds had to come from someplace else."

Dinwiddie has been defying his coach's orders and looking at bracketology projections — in the middle of class, even.

The guard just can't help studying the reports, wondering what seed the Buffaloes might draw. He thinks the Buffaloes have proven they belong in the NCAA tournament, especially after what they did against Oregon.

The Buffaloes are now 4-2 against Top 25 teams this season.

Surely, that's good enough to get the Buffs in, right?

Don't bank on anything just yet. Colorado coach Tad Boyle certainly won't.

He remembers all too clearly two years ago when he thought the Buffs were a lock to make the tournament, only to be left out. The sting of that has him looking only at the task at hand — a game against Oregon State on Saturday to close out the regular season and then the conference tournament.

As for whether his team has done enough to impress the selection committee, Boyle will never think his team has done enough until he sees Colorado in the field.

"Wish I could say yes," Boyle said. "All I know is obviously our body of work is much better this year than it was two years ago. I still feel badly for that team two years ago. I've talked about it with the guys ... all those guys were in my living room when that day occurred.

"It's important we finish strong."

No one realizes that more than the Ducks, who were thwarted in their bid for an outright conference title.

Did the pressure get to them?

"No, it wasn't any pressure, it was excitement," said Arsalan Kazemi, who finished with 10 points. "I think we thought they were just going to give it to us. It didn't happen. So we just have to go and take it. We have a really important game against Utah Saturday, so this game is all gone. We just have to think about that game."

Colorado beat Oregon 48-47 last month, snapping the Ducks' 20-game home court winning streak. This was the Buffs' second sweep of a league foe this season, taking two from Stanford as well.

"This was a gutty effort against a great basketball team," Boyle said.