49ers will play Bears without RB Christian McCaffrey

The Bears’ opponent on Sunday started the season as the favorite to win the NFC — and will end it with a wounded roster. The injury bug hit again Monday when the 49ers (5-7) put their top two running backs on injured reserve. They could miss the rest of the season. Three-time Pro Bowl player Christian McCaffrey left Sunday night’s game in Buffalo with a right knee injury. Backup Jordan Mason suffered a right ankle sprain against the Bills.

McCaffrey played his first game in Week 10 after starting the season on the shelf because of calf and Achilles tendon injuries. He won’t need surgery, 49ers coach Kyle Shanahan told reporters Monday. Mason ran for a team-high 789 yards in his place.

The two will be replaced by rookie Isaac Guerendo, a fourth-round draft pick who has 246 rushing yards. The 49ers are on a three-game losing streak. Like the Bears, they’re the only losing team in their division.