The San Francisco 49ers’ injury list continues to grow in the second half of the season. After the loss to the Buffalo Bills in Week 13, head coach Kyle Shanahan reported unfortunate injuries to his top two running backs and a key role player on the defensive line.

Reigning AP NFL Offensive Player of the Year Christian McCaffrey suffered a PCL injury in the second quarter of Sunday night’s contest. Shanahan said initial reports indicate he will not require surgery, but McCaffrey’s recovery time is estimated at about six weeks and he will be placed on the injured list.

“I feel for him. It’s been a really frustrating year for him,” Shanahan said. “…I think he felt really good and was close to taking off. He just had this really unfortunate injury last night. I know he’s as devastated as anyone, but he’ll get through this.”

“He’s a great player, a great person and an incredible 49ers player. He will be back stronger than ever to help us next year.”

McCaffrey spent the first nine weeks of the season on IR due to Achilles tendonitis before returning for the final four games. He recorded 50 carries for 202 yards on the ground in those contests and added 15 catches for 146 yards.

Fellow running back Jordan Mason is also headed to IR after suffering a high ankle sprain against the Bills. Mason was the 49ers’ primary running back for the first eight weeks of the season, filling in for the injured McCaffrey. The former undrafted free agent rose to the challenge this season and put up impressive statistics. Mason recorded 153 carries for 789 yards and three touchdowns to go, as well as 11 catches for 91 receiving yards in his 12 appearances (six starts).

With San Francisco’s top two running backs out of the lineup, rookie Isaac Guerendo is now the team’s best option at running back. Shanahan said he expects to bring Patrick Taylor Jr. off the practice squad and will look to add another to the 53-man roster to round out the room.

The third player expected to land on IR is defensive lineman Kevin Givens after suffering a torn pectoral muscle on Sunday night. Givens was recovering from a lingering groin injury and served as a key depth player for the 49ers’ D-line in 2024. He appeared in eight games (one start) this season and collected 3.5 sacks and 11 total tackles in those appearances.