Jon Gruden unveiled as Oakland Raiders head coach

Jon Gruden was unveiled on Tuesday as the new coach of the Oakland Raiders, the same club where he made his debut as an NFL head coach 20 years ago.

Gruden was lured from the television commentary booth to return to the sidelines for Oakland when Raiders owner Mark Davis reportedly offered him a 10-year deal worth $100m (£74m), the richest and longest in NFL history for any coach.

Gruden believes his deal could inspire his rivals and insists he doesn't feel any pressure.

"I know there's a big bull's-eye on my chest certainly. If people want to use that as incentive, so be it," Gruden said. "I've dealt with pressure before. I really don't feel pressure."

Gruden coached the Raiders from 1998 to 2001 and was then traded to the Tampa Bay Buccaneers in a unique 2002 deal that saw him replace the fired Tony Dungy. He went on the guide the Bucs to victory over the Raiders in the 2003 Super Bowl.

"This is very emotional for me," said Gruden, who has been out of the NFL since coaching his seventh and final season with Tampa Bay in 2008.

"I never wanted to leave the Raiders. I never thought I'd be back, but here I am and I'm ready to get to work."

Gruden went 38-26 in regular-season games as coach of the Raiders, guiding the team to two playoff berths.

He admitted he has some "unfinished" business with the Raiders, with his final game at Oakland among the NFL's most controversial losses - the Raiders falling to New England on the infamous Tom Brady "Tuck Rule" non-fumble call.

"For my career to end on that night in New England, it still ticks me off," Gruden said. "I'm so thrilled to be back here. I feel a lot of loyalty and I feel a lot of responsibility.

"I'm going to do everything I can to help this team get right again."