John Madden coached the Raiders from 1969 to 1978.
Over 10 seasons at the helm, he compiled a 103-32-7 record, won seven division titles and won Super Bowl XI.
Jon Gruden coached the Raiders from 1998 to 2001.
Over four seasons, he compiled a 38-26 record and led Oakland to the 2000 AFC Championship Game.
In a recent interview with USA Today Sports, Madden weighed in on the current state of the Raiders, and made it known what he thinks of the possibility of Gruden returning to coach the team.
"The further you get away from it — the game changes from week to week, from month to month and from year to year," Madden said. "So the more years you're out, they're playing a different game than he coached.
"The game that Jon Gruden coached isn't the game they're playing now."
On the day the Raiders introduced Tony Sparano as the team's interim head coach, owner Mark Davis responded to an inquiry about Gruden maybe coming back to Oakland.
“(Gruden) may reach out to me. I may reach out to him,” Davis said. “I may reach out to anybody. But that’s the future and I’m not going to talk about future coaches.”
A few days later, Gruden discussed whether or not he is contemplating a return to the sideline.
“I'm not even thinking about coaching,” Gruden said in an interview on ESPN Radio. “I'm thinking about heading to Washington (play on MNF) next week, watching the world champion (Seattle Seahawks) and my brother coach (Washington). That will be exciting for me."
The 0-8 Raiders host Peyton Manning and the 6-2 Broncos on Sunday.