Looks like the 49ers’ high-octane offense just hit a speed bump! Star RB Christian McCaffrey’s officially hitting IR after being on the injury radar for quite some time now. Niners’  HC Kyle Shanahan just made it official: the All-Pro RB will be sidelined with calf tightness and Achilles tendinitis.

NFL insider Ian Rapoport broke the news on X with a tweet: “Not a surprise, as Kyle Shanahan said yesterday that placing Christian McCaffrey on IR today was possible (making it likely). But it will be official today.” And sure enough, it’s official. The Stanford standout’s likely out for the next four games due to calf tightness and Achilles tendinitis.

Here’s the scoop: CMC’s out for the games against Minnesota this Sunday, at the Rams on Sept. 22, against the Patriots on Sept. 29, and vs. the Cardinals on Oct. 6. The Niners will take a fresh look at his status in mid-October to see if he can make a comeback against Seattle on Oct. 10.

The injury saga started earlier this season. McCaffrey was a last-minute scratch before the opener against the Jets, with the injury worsening despite careful management and rest. HC Shanahan was candid about the situation: “(Injured reserve) is something we are considering now. Yesterday was his worst day. It’s on and off but with him having the worst pain yesterday, it’s something we are going to be discussing in the next 24 hours.”

The NFL cleared the Niners of any wrongdoing in their injury reporting, so no funny business there. With McCaffrey hitting the IR, San Fran’s ground game’s about to go on a wild ride without their top rusher. Last year, CMC crushed it with 1,459 rushing yards, and he’s logged four 1,000-yard seasons. Yeah, he’s a big deal.

If Christian McCaffrey’s injury lingers, it’s going to be a test of depth and adaptability for San Fran. So, who steps up? The spotlight will shift to other backs on the roster. 

Who’s up next? 49ers’ backup plan without Christian McCaffrey

With CMC hitting IR, the Niners need to step up their game. Here’s a lowdown on who Shanahan can consider:

Jordan Mason: Mason snagged 147 yards and a TD on 28 carries when he debuted. This guy’s definitely got a chance to lock down the starting gig while McCaffrey’s out. Fantasy managers, take note—Shanahan’s offense’s a goldmine for rushing stats.

Isaac Guerendo: The rookie from the 2024 draft’s next on the depth chart. Though Guerendo might not get much play in Week 2, he’s a name to watch. Think of him as a future star, similar to how Mason was when McCaffrey was fully healthy.

Patrick Taylor Jr.: An NFL vet since 2020, Taylor’s had stints with the Packers and Pats’ practice teams. He’s unlikely to see significant action, but keep in mind that McCaffrey’s impact goes beyond rushing; his role in the passing game was a huge part of the offense.

In Week 1 against the Jets, other key players stepped up. Deebo Samuel was explosive on jet sweeps, and All-Pro fullback Kyle Juszczyk’s ready to shine in new play calls. Despite Christian McCaffrey’s injury, HC Shanahan’s got a solid roster to keep the Niners offense rolling.