Robert Saleh's secret to defensive success for the San Francisco 49ers

This is interesting.

Darren Yamashita-Imagn Images

Robert Saleh has been one of the most impressive defensive coordinators in the NFL this season. He is getting by without his two stars, Nick Bosa and Fred Warner.

While he has made a few tweaks, they may be unnoticeable to most fans at home. According to Football Insights, the 49ers are not blitzing more without their star pass rusher, but they are playing many different coverage looks. 

How Robert Saleh is getting the most out of the San Francisco 49ers defense

No defense is blitzing less than the 49ers. The only defense even close is the Houston Texans, run by DeMeco Ryans. These two run a familiar defense, and they run what they run. You would typically see the 49ers down around the Texans in terms of disguised coverages as well, as Saleh plays a similar brand. However, this year, he is mixing things up a lot more.

How often defenses blitz and how often they disguise coverage pre-snap to post-snap pic.twitter.com/hHW8ElqHYm

— Football Insights 📊 (@fball_insights) December 4, 2025

This makes sense. Saleh does not believe in blitzing, but he also knows that trusting his front to get home fast enough with the level of talent they have is not smart. So, he is making life easier on his front four by mixing things up on the back end.

This has gotten a lot easier since the 49ers have been able to get Malik Mustapha back into the lineup and then shift in Ji’Ayir Brown. Jason Pinnock is limited, and Marques Sigle is a rookie, so there is only so much the team can do on the back end with them. Brown is much more versatile, which is why it makes sense to pair him with Mustapha, who is clearly a smart defender and tends to be in the right place at the right time. 

Saleh trusts Brown and Mustapha to mix things up on the back end but maintain their coverage responsibilities. Beyond that, Renardo Green has come into form and Deommodore Lenoir is a trusted veteran. Upton Stout is a promising rookie and the trio has hardly missed any time together, so they are playing much more together than they were earlier in the year. 

The result has been a few surprising performances by an undermanned defense. 

To be fair, the Los Angeles Rams had plenty of success, so when they face the elite quarterback who can see through disguises, things may change. However, some quarterbacks may continue to struggle to read this group, which could play a huge role in San Francisco winning important December matchups.