BOULDER — Colorado suffered more than its first loss at No. 4 Michigan on Saturday.

The Buffaloes were also left to deal with a handful of injuries that could prove more far more damaging than a non-conference defeat.

The status of CU quarterback Sefo Liufau for Saturday’s game at Oregon won’t be decided until later this week, coach Mike MacIntyre said Monday.

What is certain: CU will play the rest of the season without junior outside linebacker Derek McCartney, who suffered a torn right anterior cruciate ligament during Saturday’s game.

It’s a major blow for the Buffs.

“It’s really disappointing,” MacIntyre said. “Derek is our biggest, strongest outside linebacker. He’s a good player for us, great leader.”

McCartney began Saturday’s game in grand fashion, picking up a fumble forced by Chidobe Awuzie early in the first quarter and returning it for a touchdown that gave the Buffs a 14-0 lead.

Unfortunately for the Buffs (2-1), it will be his last highlight of his season. McCartney, the grandson of former CU coach Bill McCartney, suffered the injury during a play in the middle of the second quarter.

“I just kind of landed funny and my knee buckled on me,” McCartney said. “I felt something that felt weird. I didn’t go back in because it didn’t feel right, and the doctors figured (an ACL tear) was probably what had happened.”

McCartney was fifth on the team with 70 tackles as a sophomore last season and was second with five sacks. He hadn’t compiled big numbers before Saturday’s score, but his ability to rush the passer and apply pressure has been key for the Buffs.

“It’s unfortunate,” McCartney said. “I’ve just got to be there for my teammates and do what I can to help them.”

Liufau suffered a right ankle injury during the third quarter of CU’s loss to Saturday. MacIntyre said Liufau “was moving around better” on Monday than he was on Sunday, but did not practice. The quarterback is considered day-to-day.

“If he’s moving good enough to play, we’ll play him,” MacIntyre said. “If he’s not moving good enough to play then we won’t play him. We’ll know as the week goes along on that.”

If Liufau is unable to play against the Ducks (2-1), who are coming off a 35-32 loss to Nebraska, the Buffs will turn to backup Steven Montez. The redshirt freshman from El Paso, Texas, is 6-of-17 passing for 117 yards and two touchdowns this season. He was 0-of-7 in relief of Liufau against Michigan.

“Steven Montez had a great spring and a good fall and he’s played in all three games now,” MacIntyre said. “So he’ll be ready to roll. I feel good about Steven’s capabilities. Now he’s got to do it in the game.”

Montez said his biggest takeaway from his performance from Michigan was a renewed appreciation for how much preparation is required to play at the major-conference level.

“Just learned the importance of studying before the game,” he said. “Just preparing and knowing what our game plan is. You have to be extremely serious about how you prepare.”

MacIntyre on Monday also confirmed kicker Diego Gonzalez will miss the rest of the season with a torn Achilles tendon. His absence has produced a kicking competition this week between junior Chris Graham and walk-on freshman Davis Price, a former Evergreen standout.

Footnotes. CU announced its home game against Oregon State on Oct. 1 will kick off at 12:30 p.m. The game will be televised on the Pac-12 Network. … The three CU players who suffered injuries Saturday — Liufau, McCartney and Gonzalez — are all roommates.