49ers lose Christian McCaffrey, Jordan Mason to injured reserve

The injury news for the 49ers was twice as bad as expected Monday.

Running back Christian McCaffrey will go on injured reserve with a posterior cruciate ligament strain that may not need surgery, but is serious enough to sideline him for the season. To make matters worse, Jordan Mason, the 49ers’ leading rusher, will also “most likely” go on IR and could miss the remainder of the season.

The 49ers are coming off a 35-10 road loss to the Buffalo Bills and will host the Chicago Bears Sunday at Levi’s Stadium with fading playoff hopes at 5-7 that just took another blow with the loss of two key offensive performers.

Also going on injured reserve will be defensive tackle Kevin Givens, who returned from a groin injury but sustained a torn pectoral against Buffalo.

Shanahan said in a conference call with reporters that he hasn’t had a chance to speak with McCaffrey, who played in just three games after missing the offseason and training camp with bilateral Achilles tendinitis and had 53 yards on seven carries before being injured on a 19-yard gain in the first half.

The recovery time for McCaffrey’s injury, Shanahan said, is six weeks. The 49ers have five games left in the regular season and are longshots to make the postseason.

“I just feel for him. he worked his butt off to get back to this point and I think he was really feeling good and about to take off,” Shanahan said. “I know he’s as crushed as anyone. He’s a hell of a player, a hell of a person and an unbelievable 49er and he’ll be back stronger than ever next year to help us.”

Ed McCaffrey, Christian’s father and a former 49er, said on the “Up & Adams” show with Kay Adams he believes his son will put in the requisite work to come back strong.

“Christian’s tough. He’ll bounce back,” Ed McCaffrey said. “You feel angry and confused, then you go back toward getting healthy again and getting back in the saddle one day. That’s where his emphasis is right now.”

Mason gained 78 yards on 13 carries against Buffalo before giving way to rookie Isaac Guerendo. In theory, if Mason goes on injured reserve, he could still be activated before the regular season finale against Arizona.

With Mason out, the 49ers’ leading rushers are quarterback Brock Purdy (53 carries, 271 yards) and Guerendo (42 carries for 246 yards).

Guerendo will get plenty of work with the first team this week. The 49ers will promote Patrick Taylor Jr. from the practice squad and will be in the market for another running back.

LENOIR EXPECTED BACK, HUFANGA STARTS WINDOW

Cornerback Deommodore Lenoir, who missed the Buffalo game with a quad contusion, is expected back Wednesday at practice. Shanahan also said the 49ers will open the 21-day injured reserve window on Talanoa Hufanga (wrist), who will need to play with a protective device when activated.

Linebacker Dre Greenlaw will continue to practice this week, although with Chicago and then a Thursday game against the Rams, he may not rejoin the 53-man roster until Dec. 22 in Miami.

Edge rusher Nick Bosa (hips, obliques) and left tackle Trent Williams (ankle) will be monitored during the week. Williams and his wife Sondra are mourning the loss of their son Trenton Jr. at birth on Nov. 24, but Shanahan said Williams plans on playing when the swelling subsides and he’s healthy enough to play.

Shanahan said Purdy came out of the game without further re-injuring his right shoulder and didn’t even need treatment upon the 49ers return Monday.

Left guard Aaron Banks and defensive tackle Jordan Elliott are both still in concussion protocol. Linebacker Demetrius Flannigan-Fowles (knee) is day-to-day.

SORENSEN’S VOTE OF CONFIDENCE

The 49ers have been outscored 73-20 over the past two weeks, losing consecutive games for 25-plus points for only the fourth time in franchise history. Shanahan stopped well short of laying the blame at the feet of defensive coordinator Nick Sorensen, whose unit gave up 389 yards rushing in the two losses and failed to produce a takeaway.

“I’m very satisfied with Nick,” Shanahan said. “I’m not at all satisfied with the results and how it’s going right now. But some of the mistakes, or what’s happened these last two weeks, I don’t think it’s a schematic issue. It’s a little bit more of a fundamental issue. And that also starts with me, goes to all coaching, to all the players. The results these last two weeks haven’t changed my opinion on Nick.”

DOBBS OVER ALLEN

How is it that Brandon Allen was considered good enough to start in place of the injured Purdy in Green Bay and then the following week was listed as No. 3 upon Purdy’s return behind Joshua Dobbs?

“Just the type of game that we thought it could be,” Shanahan said. “We had a feeling all week, just looking at the forecast. We knew it would be more of a running game and we wanted that element added to it. We thought he could help in that way.”

Any chance Dobbs had of getting in some game time in the fourth quarter with a big deficit evaporated when the 49ers had the ball for only 1:55 of the last quarter.

THE BARTCH DEBUT

One of the few bright spots was the 49ers’ ability to run the ball. They had 153 yards on 27 attempts, their most yards rushing since getting 223 against Dallas on Oct. 27.

Left guard Ben Bartch, who was inactive all season until playing seven snaps against Green Bay and hadn’t started since 2023 for Jacksonville, acquitted himself well, according to Shanahan.

“I was impressed by him,” Shanahan said. “I know he’s got a lot of ability and stuff and we’ve enjoyed working with him here, but that was our first time going into a game with him. I loved how he competed. I thought he blocked well. I thought he helped us in that game. So it was a good first start for him.”

SNAP JUDGEMENTS

58: Cornerback Charvarius Ward didn’t miss a defensive snap in his return to the lineup. He was one of four players to play every snap, joining cornerback Renardo Green, safety Malik Mustapha and safety Ji’Ayir Brown.