With only 12 guaranteed opportunities packed into a 14-week stretch of fall to play a game, the Colorado football team has very little time to dwell on the past.

On Saturday, a plethora of mistakes and a list of wounded Buffaloes contributed to them walking off the turf at Folsom Field with a loss for the second time this season, 35-30 against Arizona.

“There is disappointment on the coaching staff side and on the player side,” Buffs’ head coach Mel Tucker said. “You can feel it.”

To give itself a chance at erasing that disappointment, CU (3-2, 1-1 Pac-12) has no choice but to focus on the next opportunity.

“The best thing to do is to forget about this game, move on to the next game and get ready for Oregon starting (Sunday) and see what they do and get ready to play Friday,” senior cornerback Delrick Abrams Jr. said.

In what has been a roller coaster season so far, the Buffs face their toughest test on Friday night when they visit 13th-ranked Oregon (4-1, 2-0), which has won four in a row, plays well at home, and is suddenly performing better on defense than it has in decades.

Early odds have the Ducks favored by 20.5 points in CU’s first trip to Eugene since its stunning upset in 2016.

CU has already won a couple games pundits didn’t expect (Nebraska, at Arizona State), but to pull off an upset on Friday, the Buffs have a lot of work to do.

Saturday’s loss included eight penalties for 85 yards, a handful of dropped passes and missed assignments on both sides of the ball.

“It’s definitely disappointing because we don’t practice our butts off all week to go out there and lose,” quarterback Steven Montez said. “I think it definitely can be taken as a learning experience for us. There’s a lot of things that we can clean up, especially on offense, specifically. I think we did a lot of good things today though, too. So it’s just not all bad.”

It wasn’t all bad, but CU’s task this week becomes even tougher if it doesn’t get some players back.

Receiver Laviska Shenault (core muscle strain), defensive end Mustafa Johnson (high ankle sprain), safety Aaron Maddox (leg laceration) and cornerback Chris Miller (knee) all missed Saturday’s game.

Tight end Jalen Harris and guard Colby Pursell both dressed but didn’t play. There has been no word on their injuries, but Tucker said after the game, “We haven’t benched anyone,” which indicates both were not physically able to go.

During the game, safety Mikial Onu (torso), nose tackle Jalen Sami (knee) both left the game. Receiver KD Nixon and tight end Brady Russell both left the game, as well, presumably with injuries, although there was no indications from CU about their health status. Onu was the only one of that group that returned, as he hobbled through Arizona’s final offensive series.

Miller is out for the year, but it’s possible Shenault, Johnson and Maddox all return for Friday. The status of the others was unknown as of Sunday.

“Injuries are a part of the game, so I’m not going to sit here and act like that’s going to be an excuse that we’re going to use,” Montez said. “If you play football and you play at a high level, there’s going to be injuries, so no excuses there.”

Tucker and several other players delivered the same message after Saturday’s loss. Tucker, of course, would like to have a healthy squad every week, but with the quick turnaround – and even quicker this week – his focus is on getting his team ready to play another game.

“We’ll figure out where the breakdowns were, how to clean up the penalties and things like that,” he said. “And then, we’ll get the injury report, and we’ll figure out who we have ready to move forward. And we’ll put together plans to put those guys in position to make plays.”

CU didn’t make enough plays on Saturday against Arizona, but another opportunity is just around the corner.

“We’re on to the next one,” said sophomore safety Isaiah Lewis, who filled in for Onu in the second half. “We’re not pointing fingers anywhere. Everybody’s trying to correct the mistakes they made and then we’re trying to go to Eugene and get a W. Nothing else in mind.”

CU opponent glance

Opponent: No. 13 Oregon Ducks

Game time: Friday, 8 p.m. MT at Autzen Stadium in Eugene, Ore.

TV: FS1

Coach: Mario Cristobal, 2nd year (13-5; 40-53 career)

Record: 4-1, 2-0 Pac-12

Last week: Defeated Cal, 17-7, at home

Notable: The Ducks have allowed just 22 points in the last four games (5.5 per game). During that stretch, only one touchdown – by Cal last week – has been scored against the Oregon defense. … This is the first time since 1960 that the Ducks have held four consecutive opponents below 10 points. Oregon had held opponents below 10 points just four times in the previous seven seasons combined. … Quarterback Justin Herbert has thrown at least one touchdown pass in 33 consecutive games. … Herbert is the only QB in the Pac-12 with more career starts (33) than Colorado’s Steven Montez (32). … Since the start of the 2017 season, the Ducks are 15-2 at home. … First-year Ducks’ defensive coordinator Andy Avalos was a graduate assistant at CU from 2006-08.