“Shanahan did, however, know two things: that defensive pass game specialist Nick Sorensen was a strong, up-and-coming in-house candidate and that he wanted to get back to the basics of the 4-3 defense featuring the wide-9 alignment upfront backed up by mostly zone coverage.
As Shanahan and the Niners went through the interview process, it became increasingly clear that Sorensen was the right choice to execute the second part of that equation. It also became evident that there was an opportunity to bring in an experienced, outside voice - former Chargers coach Brandon Staley — capable of providing fresh ideas to help the 49ers’ defense return to its previous dominance.