Gruden coached the Raiders to a 38-26 record and two playoff appearances from 1998-2001.
It will be Gruden's first Raiders home game since their preseason Monday night game against the Dallas Cowboys on Aug. 13, prior to which he hadn't visited since 2004 when he was the head coach of the Buccaneers.
Having last coached in Tampa Bay in 2008, reports surfaced recently that Gruden was interested in a return to the NFL sidelines. That is where he is expected to be Sunday, on the field prior to the game.
The Al Davis memorial flame is an eternal flame at O.Co Coliseum that burns in honor of the Raiders legend and long-time owner who passed away on Oct. 8, 2011 at the age of 82.
Gruden will join Raiders great Marcus Allen as icons to have lit the flame this season. John Madden did so last year.