DeForest Buckner

49ers converting to 4-3 defense in 2017

The San Francisco 49ers are expected to switch to a 4-3 scheme under new defensive coordinator Robert Saleh.

What It Means:

Saleh was with the Seattle Seahawks from 2011-2013 before he followed former Jaguars head coach Gus Bradley to Jacksonville to coach linebackers. Seattle and Jacksonville ran a 4-3 "under" front, which could create poor fits for San Francisco's most recent two first-round picks, DeForest Buckner and Arik Armstead, who were drafted to be 3-4 defensive ends.

The 49ers were fifth-worst in schedule-adjusted Defensive Net Expected Points allowed per play this past season.