Bradley was formerly head coach of the Jacksonville Jaguars from 2013-16, compiling a 14-48 record. He had been the defensive coordinator for the Los Angeles Rams for the past four seasons before accepting the Raiders' position.
The Raiders fired Guenther during the 2020 campaign following a 44-27 Week 14 loss to the Indianapolis Colts. The 49-year-old was in the midst of his third season as the Raiders defensive coordinator.
Despite having a talented defense on paper, the Raiders gave up 30-plus points in 10 games during the 2020 season. They gave up 40-plus points in three of those 10 games.