Fassel, the Raiders' quarterbacks in 1995, met with officials at the team's headquarters to talk about replacing the fired Art Shell.
Oakland fired Shell last week after a 2-14 season that was the worst season in the more than four decades that owner Al Davis has been with the franchise. The Raiders set a team record for losses and fewest points scored with a league-low 168.
Earlier in the week, the Raiders interviewed Southern California quarterbacks coach Steve Sarkisian. Oakland defensive coordinator Rob Ryan is expected to interview over the weekend.
Detroit Lions offensive coordinator Mike Martz could also be brought in for a second straight year for an interview, and the team also plans to talk to at least one or two minority candidates.
Fassel was fired in October as offensive coordinator in Baltimore after the Ravens scored just 10 offensive touchdowns in their first six games. Head coach Brian Billick took over the play-calling duties and the Ravens scored 22 offensive touchdowns in their final 10 games to win the AFC North.
Fassel was in his second year as Ravens offensive coordinator after serving a season as a senior consultant to the offense.
From 1997 to 2003, Fassel guided the Giants to two NFC East titles, a conference championship, an appearance in the Super Bowl and a wild-card playoff berth while posting a 58-53-1 record. He was NFL coach of the year in 1997 and lost the 2001 Super Bowl to Baltimore.
The Raiders are hoping to complete this year's search for Shell's replacement in a shorter time frame than the more than five weeks it took to replace Norv Turner a year ago.
Most of the candidates are offensive-minded. Most of the NFL's third-ranked defense is set to return next season, putting the focus on rebuilding an offense that was one of the league's worst.
Oakland has the No. 1 pick in April's draft and could use it on quarterbacks Brady Quinn of Notre Dame or JaMarcus Russell of LSU.