From 1996 to 1997 Bresnahan served as linebackers coach of the Indianapolis Colts. He was the Oakland Raiders' defensive backs coach from 1998 to 1999 before he was promoted by then Head Coach, Jon Gruden, to defensive coordinator and spent 2000 to 2003 in that role. During that time the Raiders won three consecutive AFC West Championships, appeared in two AFC Conference Championship games and Super Bowl XXXVII.
From 1996 to 1997, Bresnahan worked as a linebackers coach for the Indianapolis Colts. He then became the defensive backs coach for the Oakland Raiders from 1998 to 1999 before being promoted by Head Coach Jon Gruden to defensive coordinator in 2000 and remaining in that role until 2003. During his time as defensive coordinator, the Raiders won three consecutive AFC West Championships, reached two AFC Conference Championship games, and played in Super Bowl XXXVII.