Why the 49ers Defense Could be Surprisingly Good this Season

SANTA CLARA -- Most analysts expect the 49ers' offense to be much better than their defense this season.

That's because their offense has lots of highly-paid veterans -- Brock Purdy, George Kittle, Trent Williams, Christian McCaffrey, etc. -- while the defense has lots of young players on their rookie contracts. Which is why the 49ers keep saying they're prepared to take their lumps early this season while the young players learn on the fly.

But in the 49ers' first preseason game this past Sunday, only one side of the ball had its stuff together, and it was the defense. The 49ers' second-stringers forced the Broncos' starters to punt and commit a safety in their first two drives. Highly impressive.

Aug 9, 2025; Santa Clara, California, USA; Denver Broncos quarterback Bo Nix (10) calls out signs in the first quarter against the San Francisco 49ers at Levi's Stadium. Mandatory Credit: David Gonzales-Imagn Images | David Gonzales-Imagn Images

Meanwhile, the 49ers' second- and third-string offense was atrocious all night with the exception of one long pass from Mac Jones to Jordan Watkins. The rest of the offense's performance as a mess.

And that's because the offense lacks depth, while the defense seems to have some quality depth players such as Kalia Davis, Tatum Bethune, Darrell Luter Jr. and Chase Lucas.

If the offense is 100 percent healthy, it should be excellent. But their wide receivers and running backs are banged up already, and they don't have a quality backup offensive lineman on the roster. So if any starter were to miss a game, particularly Trent Williams, the 49ers' offense would be in major trouble.

Aug 9, 2025; Santa Clara, California, USA; San Francisco 49ers offensive lineman Trent Williams (71) watches from the sideline in the first quarter against the Denver Broncos at Levi's Stadium. Mandatory Credit: David Gonzales-Imagn Images | David Gonzales-Imagn Images

As opposed to the defensive line, which is eight players deep. The starters most likely will be Nick Bosa, Kalia Davis, Jordan Elliott and Mykel Williams, while the second wave will consist of Bryce Huff, CJ West, Alfred Collins and Yetur Gross-Matos. That's a big defensive line that can stop the run and pressure the quarterback.

At linebacker, the 49ers still have future Hall of Famer Fred Warner, plus they have Dee Winters, who is having a terrific offseason.

Aug 9, 2025; Santa Clara, California, USA; San Francisco 49ers linebacker Fred Warner (54) watches from the sideline in the first quarter against the Denver Broncos at Levi's Stadium. Mandatory Credit: David Gonzales-Imagn Images | David Gonzales-Imagn Images

At cornerback, the 49ers have Deommodore Lenoir, Renardo Green and Upton Stout -- three dogs who run in the 4.4s. And at safety, rookie fifth-round pick Marques Sigle asserted himself as a potential starter in his preseason debut this past Saturday. He eventually will play next to Malik Mustapha, an extremely talented safety who is recovering from ACL surgery.

Of the 14 players I just named, 9 of them are on their rookie contracts. This is a young, talented, deep, cheap defense that will grow together for the next few seasons under Robert Saleh, one of the best defensive coordinators in football.

Don't be surprised if the 49ers' defense ranks top 10 this season and their offense doesn't.

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