The Raiders met with former 49ers cornerback Shawntae Spencer on Friday, the same day they signed veteran cornerback Ron Bartell.
CSNBayArea reported that Spencer visited the Raiders in Alameda on Friday about the prospect of moving across the bay.
Spencer, 30, started 72 of the 98 games he played in for the 49ers the past eight seasons, including all 32 in 2009 and '10. However, he didn't start any games last season and became an afterthought in the 49ers defense.
New Raiders defensive coordinator Jason Tarver was with Spencer for seven seasons, so he no doubt has a firm idea on whether Spencer can help the Raiders.
The 49ers released Spencer in a salary-cap move. It's likely the Raiders could get Spencer for somewhere near the veteran minimum, given his lack of leverage.
The Raiders remain thin at cornerback in light of their releasing veterans Stanford Routt and Chris Johnson since last season ended.