San Francisco's defense evolves beyond Saleh. Expect a more versatile front and new pressure schemes to unleash Nick Bosa.
When Robert Saleh officially moved on, it marked the end of an era more than a surprise. The question now isn’t whether San Francisco’s defense will change, it’s how much. If anything, Raheem Morris will inherit a roster that lends itself to evolution, especially in how the 49ers deploy their front and manufacture pressure.
The foundation remains: stop the run
No matter who takes over, the backbone of the defense isn’t going anywhere. Since 2021, the 49ers have consistently ranked near the top of the league in rushing EPA allowed and success rate. That’s not accidental.
San Francisco’s defensive line is still built to control gaps with power rather than slanting or gambling. That allows linebackers to play fast and downhill without hesitation. Any incoming coordinator who strays too far from that principle would be swimming upstream.
Expect more multiplicity up front
Under Saleh, the 49ers lived primarily in four-man fronts, relying on talent to win rather than disguise. That worked, when the roster was healthy, but the roster now supports more five-man and “reduced” looks.
The 49ers already have the personnel to switch back and forth between even and odd fronts. That matters. When you can stay in base but present five-man surfaces, you force offenses to declare protections earlier and limit their ability to double Bosa consistently. The goal is to give Bosa cleaner rush paths.
Pressure doesn’t always mean blitzing
Saleh wasn’t blitz-averse, but he was selective. Morris may keep that same philosophy while changing how pressure arrives.
One area ripe for expansion is simulated pressure. Simulated pressure shows up in various ways, potentially showing blitz or dropping defensive ends are two easy examples.
Stunts and late movement on running downs are another lever. Changing the math in the box without bringing extra bodies is an efficient way to stay aggressive while protecting the back end.
Coverage: different answers
The 49ers will continue to live in split safety and Cover 3 variations. That’s not changing. What could change is how rigid those alignments are.
Saleh preferred keeping cornerbacks on sides rather than traveling. That worked, but it also limited the defense’s ability to erase true No. 1 receivers without help. A new coordinator may be more willing to let a top corner to “man mark” or shadow which is the more commonly used term.
The safeties
Change feels inevitable at free safety. The current group excels at run fits and playing downhill but what’s missing is that consistent presence who can erase mistakes when pressure doesn’t get home.
If the 49ers plan to increase disguise, stunts, or simulated pressure, the margin for error shrinks. That makes a true safety a necessity and whether that answer comes via the draft or free agency, it’s the one glaring schematic gap on the roster.
Final thought
The post-Saleh defense won’t look radically different on the surface and that’s on purpose, great coaches work to the strengths of the people they have, not what they wish they had. With Bosa, Warner, and a deep rotation up front, the pieces are already there. The next defensive coordinator’s job isn’t to rebuild in any way, it's to unlock the potential that has been hiding in plain sight.