49ers Counting on Run Defense Changes vs. Colts

Three wins from the 1 seed

Oct 12, 2025; Tampa, Florida, USA: Tampa Bay Buccaneers wide receiver Emeka Egbuka (2) runs for a gain past San Francisco 49ers linebacker Tatum Bethune (48) during the second quarter at Raymond James Stadium. Mandatory Credit: Jonathan Dyer-Imagn Images | Jonathan Dyer-Imagn Images

The 49ers are in the playoffs, and the goal shifts to acquiring the highest seed. Three wins to close out the year and they complete an improbable run to the NFC’s 1 seed. The first step is beating the Indianapolis Colts tonight, which begins with stopping the league’s leading rusher, Jonathan Taylor.

The run defense has been poor the last few weeks, reflecting injuries and the resulting personnel experiments. Last week, the Niners were gashed for 6.8 yards per carry. Personnel included Curtis Robinson at linebacker and Jason Pinnock at safety. Tennessee averaged 9.7 yards per rush when Pinnock was on the field.

Robinson will be replaced by the timely return of Tatum Bethune, who may surpass his season and career high of 16 tackles in this game. The question for Robert Saleh is who replaces Pinnock? Recent free agent signing Eric Kendricks makes sense, one of PFF’s top 15 linebackers last year, a proven run stopper.

This would put three linebackers on the field to help stop Taylor; but makes the defense more vulnerable in the passing game, particularly against rookie tight end Tyler Warren. None of the three linebackers are skilled in pass coverage. As he has in recent weeks, Saleh may shift between a big nickel against the run and a small nickel on passing downs with Upton Stout.

49ers on offense

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Brock Purdy throws against backup corners for the Colts as Sauce Gardner and Charvarius Ward are both out with injuries. In the last three weeks, Indianapolis has given up over 278 passing yards per game, the second most in the league.

Defensive tackle DeForest Buckner has been out for over a month with a neck injury and returns tonight to play his former team, facing Spencer Burford.

Indy has a stout run defense, tied for the league lead at 3.7 yards per carry. With Christian McCaffrey recovered from a bad back, he should get more touches this week, particularly receiving targets. The Colts defense is strong there as well, 4th in the league in receiving yards against by backs.

Where the 49ers can attack is with George Kittle. Indy is 24th in receiving yards by tight ends; and at WR, where the Colts rank 27th.

Purdy could throw more attempts than normal in this game if the Colts are able to limit McCaffrey.

Colts on offense

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44-year-old grandfather Philip Rivers gets his second start, facing a defense that was in pre-school when he was a rookie.

Shane Steichen’s game plan last week was conservative by design. 17 of Rivers’ 19 completions were six yards or fewer, and nine of those were behind the line. He was 2-8 with a pick on throws beyond ten yards.

I’m looking for Steichen to call play action on run downs, faking to Taylor to draw the defense and throwing to Warren in favorable matchups against the Niner linebackers. He’ll also set up both on screens.

Saleh prefers to play the secondary back to prevent explosives. Facing Rivers, he can bring them up and will need to stack the box. The run defense will be helped by Darrell Luter Jr. starting at corner for the injured Renardo Green.

Colts left tackle Bernhard Reimann is out, one of the league’s best and most underrated linemen, and a key part of their run game.

Taylor will get his. Steichen will open up the passing attack more now that he has a feel for what Rivers can do. The unknown is how Rivers responds physically in his second game. Recovery after playing his first game back in five years may be an issue.

Alec Pierce is the deep threat, Michael Pittman Jr. the leading receiver, followed by Warren.

Prediction (7-7)

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The Niners need to force Indy into passing situations on 3rd to get off the field. Short 3rd downs will be difficult to stop with Taylor and Warren being the primary threats. Rivers doesn’t have the legs to avoid pressure, but he has the smarts to get the ball out. If Indy is working the Niner linebackers successfully, Saleh may need to blitz more often.

Indy will try to take McCaffrey out of the game, and Kyle Shanahan needs to respond by feeding Kittle, who typically shines in prime time. With the Colts struggling against the pass, that should help Purdy’s efficiency on 3rd down and in the red zone.

Both offenses grind out long drives without explosives, and both defenses will struggle to get off the field.

49ers 27 Colts 20