The San Francisco 49ers just got an unwelcome update on the Indianapolis Colts’ defensive front.
According to NFL insider Adam Schefter, Colts head coach Shane Steichen told reporters that defensive tackle DeForest Buckner will return from the neck injury that sidelined him and play Monday night against San Francisco, meaning the 49ers will see a familiar face in primetime.
Key details for 49ers fans
- What happened: Shane Steichen indicated DeForest Buckner is expected back and will play Monday night vs. San Francisco (per Schefter).
- When/where: 49ers at Colts on Monday, December 22, 2025, at Lucas Oil Stadium.
- Why it matters: Buckner is a premier interior disruptor and a run-stuffer, exactly the type of DT who can wreck an offense’s rhythm on early downs.
- Recent context: The Colts opened Buckner’s return window earlier this month after placing him on IR with the neck injury earlier in the season.
Colts Send Clear DeForest Buckner Message Before MNF vs. 49ers
From a 49ers perspective, the timing of this is brutal: it’s not just that Buckner is back, it’s that he’s back for this matchup.
The Colts designated Buckner to return to practice last week after placing him on injured reserve due to a neck injury, and Week 15 was the first point he was eligible to return to practice under the IR rules after Indianapolis’ bye. By Friday, the message was clear: Steichen expects his veteran DT to be available for the spotlight game.
And Buckner wasn’t just “another starter” before he went down. In the Colts’ own release on his return window, they listed him with four sacks, 13 QB hits, and nine tackles for loss over nine games this season, impact numbers that show up on film even when he’s not finishing the play.
What It Means for the 49ers Offense
The 49ers’ offense (and especially the interior offensive line) now has to prepare for the version of Indianapolis’ front that the Colts built around, because Buckner is the centerpiece.
Even if San Francisco wants to lean on Christian McCaffrey early, interior penetration can derail the 49ers’ timing-based run game by forcing cuts in the backfield. McCaffrey entered the matchup as the 49ers’ leading rusher.
It also changes the math in pass protection. Buckner doesn’t need a blitz to create chaos. He can collapse the pocket from the inside, which is one of the fastest ways to disrupt an offense’s downfield concepts.
That’s why the 49ers’ Monday plan may have to emphasize:
- quicker-developing throws
- movement pockets
- run concepts that stress edges and force DTs to run laterally
In other words: if Buckner looks like himself, he can dictate what the 49ers are allowed to call.
The “Former Team” Angle Adds Real Pressure
This isn’t just a standard injury return. Buckner is coming back to face the franchise that drafted and developed him, then dealt him.
The 49ers traded Buckner to Indianapolis in March 2020 for the Colts’ first-round pick (No. 13 overall). That move reshaped both defensive lines, and it’s why this matchup always carries extra juice when it pops up on the schedule.
Now, with Steichen indicating Buckner will play, the 49ers aren’t just dealing with a motivated Pro Bowl-caliber DT. They’re dealing with one who knows what this organization values, how it practices, and what the big moments feel like in a primetime spotlight.
One more layer: the game itself has tangible stakes in the standings. The 49ers still have an outside chance at earning the No. 1 seed in the NFC with a record of 10-4 currently. The Colts meanwhile are fighting for a playoff spot at 8-6.
What happens next: Buckner’s official status will still be tied to the Colts’ final injury report and roster mechanics, but the headline for 49ers fans is simple: Indianapolis expects its best interior defender back for Monday night.
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