ALAMEDA, Calif. -- The Oakland Raiders finished the regular season with the No. 6-ranked total offense in the NFL and scored the seventh-most points in the league, as quarterback Derek Carr ascended into the NFL's MVP conversation before suffering a broken fibula in Week 16.

Despite the Raiders going 12-4, claiming a wild-card spot in their first playoff showing since 2002 and their oft-prolific showing when they had the ball, offensive coordinator Bill Musgrave will not be retained after his contract expired, sources told ESPN's Adam Caplan, confirming an NFL.com report.

A source told Caplan that Raiders head coach Jack Del Rio told the rest of his staff Tuesday afternoon that quarterbacks coach Todd Downing has been promoted to offensive coordinator. Sources told ESPN that at least two head-coaching candidates were interested in Downing for their offensive coordinator vacancies. It is not known if Del Rio took that into consideration when deciding to promote Downing.

Del Rio, who also had Musgrave as his OC for with the Jaguars in 2003 and '04, was not afraid to criticize the offense this season. After a Week 14 loss at Kansas City, Del Rio said he wished he had seen more "big-boy ball" from the Raiders in terms of the running game.

Then, after a Week 16 regular-season finale loss at Denver that cost the Raiders an AFC West title and the No. 2 seed in the playoffs, Del Rio wondered why running back Latavius Murray had only five carries in that game. The Raiders had Matt McGloin and rookie Connor Cook under center that day.

Still, as explosive as the offense was late in games under Carr -- he had seven game-winning drives in the fourth quarter or overtime this past season -- it was often slow starting. Critics also charged that if the Raiders got a lead, Musgrave would get too conservative.

ESPN's Caplan also confirmed an NFL.com report that Oakland will keep defensive coordinator Ken Norton, Jr. despite the team's No. 26-ranked total defense.