Del Rio spent the last three years as the man in charge for Oakland.
The foundation, apparently, crumbled in a matter of months. Stories about Gruden, who hasn't coached in a decade, returning to the sideline have become an annual tradition, but perhaps this time there's actually some traction to them.
This year did not go as well as they would've like, finishing with a 6-10 record on the season.
Week 17 Ups and Downs: Minnesota Vikings vs Chicago Bears
But while the Vikings could still lean on a running game that churned out 147 yards on 36 attempts, the Bears had no such success. Jeremiah Sirles started at left guard for Nick Easton, who will miss the playoffs because of a broken ankle.
But star quarterback Derek Carr regressed under first-year offensive coordinator Todd Downing, and Ken Norton, Jr. was sacked as defensive coordinator after 10 games.
Despite all the improvements the Raiders made in 2016 prior to quarterback Derek Carr's season-ending fibula surgery, they took several steps back in 2017-especially on offense. Other marks, like completion percentage and yards per attempt, saw a dip.
The Raiders are believed to be on the verge of hiring Jon Gruden, their coach from 1998-2001, as Del Rio's replacement.