NFL Media Insider Ian Rapoport reports that the Raiders have some interest in acquiring Peterson, according to a source informed of their thinking. Rapoport characterized the Raiders as being "on the outskirts" of the chase for Peterson, but it is an option they have discussed internally. Oakland has plenty of money to spend and notably went after DeMarco Murray during free agency. This news echoes a Bleacher Report article tying the Raiders to Peterson.
Perhaps the Raiders' interest has been cautious to this point because they know it would be difficult to deliver Peterson to their rabid fan base. The Cowboys or Cardinals could offer a chance for a title in exchange for Peterson possibly taking less money on his contract. It's hard to imagine Peterson taking a pay cut to go to Oakland, no matter how much his agent believes its in Peterson's best interest to leave Minnesota.