Dianna Marie Russini of NBC Washington reports Shanahan met with the Raiders, and ESPN's Adam Schefter reports Shanahan has also interviewed with the Bills. Shanahan also reportedly interviewed for the San Francisco 49ers job last week.
The 62-year-old Shanahan was fired by the Redskins in December 2013 after four seasons and one playoff appearance with the team and did not coach anywhere last season.
Shanahan coached 20 games with the Raiders in 1988 and 1989 when the team was still in Los Angeles.
He then went on to become the offensive coordinator for the 49ers, before leaving for the Denver job in 1995. Shanahan went 138-86 during his 14 seasons in Denver, coaching the team to two Super Bowl titles.
Oakland is seeking its seventh head coach in the past nine seasons after firing Dennis Allen in September. Tony Sparano took over on an interim basis and led the team to three victories in his 12 games as coach.
Doug Marrone opted out of his contract with the Bills following a 9-7 season.
- Scooby Axson