[5] Brandon began his coaching career as a graduate assistant at Northern Illinois from 2006 to 2008 before working with defensive linemen and special teams at Division III St. Thomas (Minnesota) in 2009.
[10][11] In his only year as coordinator in 2020, Staley helped guide the Rams defense to 1st in points and total yards allowed, positioning himself as an attractive head coaching candidate around the league.
On September 12, 2021, Staley made his regular-season head coaching debut against the Washington Football Team and led the Chargers to a 20–16 victory.
However, against the Las Vegas Raiders in Week 18 in a win or tie or go home situation, Staley came under scrutiny for two decisions during the game.
The first involved a failed fourth down conversion on the Chargers' own 18-yard line, giving the Raiders a short field, which they would score on to extend their lead to six.
[15][16] However, when discussing the moment on a podcast, Raiders' interim head coach at that time Rich Bisaccia stated that "the timeout was really irrelevant".