How the 49ers’ Defense can Easily Shutdown the Colts

Game planning for the Colts shouldn't be difficult at all for the 49ers' defense.

Nov 16, 2025; Glendale, Arizona, USA; San Francisco 49ers defensive coordinator Robert Saleh speaks with 49ers safety Malik Mustapha (6) in the third quarter against the Arizona Cardinals at State Farm Stadium. Mandatory Credit: Matt Kartozian-Imagn Images | Matt Kartozian-Imagn Images

The San Francisco 49ers made relatively light work against the Tennessee Titans to get the win.

Although it did get somewhat out of hand later in the second hand. Nevertheless, the 49ers took care of business as expected. 

That theme will remain this upcoming week when they face the Indianapolis Colts. You couldn’t say that a little less than two months ago. 

The Colts were clicking on all cylinders, but have been in a free fall after starting 7-1. They are also trotting out 44-year-old Phillip Rivers.

It should make for a fairly easy outing for the 49ers’ defense. In fact, there is a low-hanging game plan for them to create that will easily shut down the Colts.

This game plan will silence Indianapolis’ offense

Dec 14, 2025; Seattle, Washington, USA; Indianapolis Colts quarterback Philip Rivers (17) walks to the locker room following a loss against the Seattle Seahawks Colts at Lumen Field. Mandatory Credit: Steven Bisig-Imagn Images | Steven-Imagn Images

What the 49ers need to do is simple: stack the box, sell out for the run, and force Rivers to beat them. Game plans aren’t always as cut and dry, but this is one of those rare occasions where it is.

Jonathan Taylor is easily the biggest threat to worry about. The 49ers have to limit the damage he can do, especially after how leaky their run defense has been recently.

They need to force Rivers to throw and expose himself. Now, he had a pretty solid performance in his return last week versus the Seattle Seahawks. 

Rivers completed 18 of his 26 attempts for 120 yards and a TD. That’s impressive for a guy who is playing in his first game since the 2020 season. 

However, he has a glaring weakness. It’s with his arm. It’s made of noodles. Rivers completed just 2 of his 8 attempts over 10 air yards for 33 yards and an interception.

Philip Rivers completed 18 of 26 pass attempts for 120 yards and a touchdown in his first NFL game in 1,800 days (since the 2020 season).

🔹 Under 10 Air Yards: 16/18, 87 yards, TD
🔹 Over 10 Air Yards: 2/8, 33 yards, INT#INDvsSEA | #ForTheShoe pic.twitter.com/YcBYrAAwIM

— Next Gen Stats (@NextGenStats) December 15, 2025

18 of his throws were underneath, where he completed 16 of them for 87 yards and a touchdown. This is where the 49ers can shut down the Colts’ offense.

By loading the box and rallying for everything underneath, it will make it extremely difficult for the Colts to score, let alone move the chains. And if Rivers wants to take a shot deep, let him.

He’s a washed quarterback with no arm. As brilliant as his mind is, his body can only keep up to a certain degree. The 49ers shouldn’t have much of an issue defending Rivers.

If they do, they will be a laughingstock that shouldn’t be taken seriously in the playoffs.

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