The Raiders will introduce Gruden at a press conference on Tuesday at noon.
While the Raiders are widely expected to name Gruden their next head coach as early as next week, neither Gruden nor the team has confirmed those reports.
After getting fired from the Bucs in 2009, Gruden went to ESPN and became the main color commentator of Monday Night Football.
His tenure ended shortly after the "Tuck Rule" loss to the New England Patriots when he was traded the following month to Tampa Bay for two first-round draft picks, two second-rounders and $8 million. He won the Super Bowl in his first season with the Buccaneers, beating the Raiders.
Cardinals QB Carson Palmer on retirement: 'I just know'
In 2015, he started all 16 games and Arizona was 13-3, advancing to the NFC Championship game, where it lost to the Panthers. Palmer had two major knee injuries in his career, tearing the ACL in his left knee twice, once in 2006 and again in 2014.
Today, the Raiders made it official, announcing Jon Gruden as the next head coach.
It started from the very beginning, when Gruden quickly dismissed McDonough's brief tribute by noting that nothing was official with regard to the Oakland job just yet.
Gruden, 54, is set to return to coaching after an absence of almost a decade.
Gruden previously coached the Raiders from 1998 through 2001, compiling a 38-26 regular-season record and a 2-2 record in two playoff appearances. He has a 95-81 career record. He was sent to the Buccaneers in a rare trade of an National Football League coach by late Raiders owner Al Davis. Gibbs returned to coaching in 2004 and his second stint in Washington wasn't almost as effective as his first.
The Raiders extended Derek Carr's contract last summer, paying the two-time Pro Bowl quarterback $125 million over five seasons. Shell went 2-14 that season and was sacked after one year. The team went 30-34 in his four seasons, making the playoffs twice and winning one game before retiring again.