NFL Network Insider Ian Rapoport and NFL Network's Michael Silver were first to report the news.
"After careful thought, I have made a difficult decision to part ways with Ken Norton, Jr. as defensive coordinator," coach Jack Del Rio said in a statement. "I have the utmost respect for Ken as a person and as a coach, but I feel that moving John Pagano into the play-calling role will best utilize his wealth of experience. I appreciate Ken's passion and commitment to the Raiders since coming aboard and wish him the best going forward."
"It's always, you kind of take it personal. But you also know that it's a business decision. I'm pretty sure coach Jack Del Rio loves coach Norton but he made a decision that was best for the team at the time," linebacker Xavier Woodson told NBC Sports Bay Area.
The move is not a surprising one, considering the Raiders' defensive play this season. Oakland ranks 26th in total defense, giving up 367 yards per game. They're the only team in the league that has yet to intercept a pass. They're tied for dead last in the league with the New York Giants with just 14 sacks on the year, despite having reigning Defensive Player of the Year Khalil Mack coming off the edges. They've given up 30 or more points in four of their last six contests.