The Oakland Raiders officially announced Jon Gruden as their new head coach on Tuesday. "I'm all in," said Gruden at a press conference. 

Earlier, FL Network Insider Ian Rapoport said that the Raiders were preparing a 10-year contract which is expected to eclipse $100 million. Gruden's coordinators will receive four-year deals, Rapoport adds.

Gruden's expected hiring has been the worst-kept secret in the NFL after the Raiders fired coach Jack Del Rio following the team's Week 17 loss.

The head of the diversity group that works with the NFL on its hiring practices confirmed to NFL Network's Steve Wyche last Thursday that Oakland is in compliance with the Rooney Rule, which requires teams to interview at least one minority for any head coaching vacancy.

Gruden compiled a 95-81 record during his first run as an NFL head coach from 1998-2008. After coaching the Raiders for four seasons, owner Al Davis traded Gruden to the Tampa Bay Buccaneers. The coach guided the Bucs to their first and only Super Bowl title during the 2002 season. He won five divisional titles during his 11 combined seasons with the Raiders and Bucs.

Since 2009, Gruden has served as a color commentator for the ESPN's Monday Night Football broadcasts.

The energetic coach will now be tasked with turning around a mercurial Raiders team, led by quarterback Derek Carr, that fell to a disappointing 6-10 in 2017 after a 12-4 playoff trip in 2016.

Gruden has been gathering a coaching staff in advance of Tuesday's expected announcement. Cowboys special teams coordinator Rich Bisaccia will be allowed out of his contract to join Gruden, per Rapoport. Former Bengals defensive coordinator Paul Guenther, now a coaching free agent, is expected to run the defense. Rams quarterbacks coach Greg Olson will also join Gruden as offensive coordinator, according to Rapoport.

(NFL contributed to this report.)