When Marc Trestman and his staff were shown the door at the end of the 2014 NFL season, the Bears knew they needed to make big changes on the defensive front. Brian Urlacher had retired a few years prior, and the team didn’t view Lance Briggs as healthy enough for another contract. Without elite linebacker play, they couldn’t justify a base 4-3 scheme any longer and hired defensive head coach John Fox to stabilize the organization. To lead Fox’s defensive staff, the Bears brought veteran coordinator Vic Fangio along to spearhead the effort to switch their terminology and base packages to 3-4.