Kyle Shanahan hints at potential schematic shakeup for 49ers defense

There may be significant change coming for the San Francisco 49ers’ struggling defense.

Since Week 2 we’ve seen the 49ers mix up their personnel to try and help that unit. Rookie defensive backs Malik Mustapha and Renardo Green have gotten some run. Second-year linebacker Dee Winters saw time in De’Vondre Campbell’s Will LB spot in Week 3 before exiting with an ankle injury.

Now a bigger alteration could be on the horizon following defensive tackle Javon Hargrave’s injury. His absence leaves a sizable hole in an already thin defensive line, and the 49ers may not have the personnel to make up for his absence in the current iteration of their defense.

Head coach Kyle Shanahan on Wednesday in a press conference indicated Hargrave’s season-ending triceps tear may act as a catalyst for some scheme changes.

“I thought our D-Line last week affected the quarterback the most that they had in their three games,” Shanahan said. “I thought that they had one of their better games. But it’s a huge loss, losing Javon. Guys are going to have to step it up and when you don’t have the rush, then you’ve got to turn to other things schematically.”

The number of players the 49ers can realistically rely on to ‘step up’ in Hargrave’s absence is small. Defensive end Nick Bosa will need to look more like a Defensive Player of the Year. DE Leonard Floyd will need to look more like he has the past four seasons. The entire defensive tackle rotation will need to be better. It’s going to be a group effort, but it’s hard to imagine the 49ers are going to affect the quarterback at the rate their current scheme requires.

Perhaps the club experiments some with a 3-4 defensive front. That’s something assistant head coach Brandon Staley has done during his career as a defensive coordinator and head coach.

They may have to alter things in the secondary as well changing when and how much they run zone coverages vs. man coverages.

Whatever it winds up being, all the possibilities have to be on the table for the 49ers. They weren’t playing championship-level defense to start the year even with Hargrave in the mix. Now they have to figure out how to do it without him, and that just might require San Francisco to make big changes in how its defense operates.