UPDATE (11:45 a.m. on Thursday) -- The Raiders confirmed the signing of all three free agents, announcing the additions in a press release.
To make room on the roster, the Raiders waived WR Jared Green, WR Noel Grigsby and P Daniel Zychlinski.
Grigsby attended San Jose Sate University and set school records for career receptions and career receiving yards.
The Raiders tinkered with the back end of their roster with three minor additions to be announced later Thursday.
They signed receivers David Gilreath and Oakland native Rahsaan Vaughn and kicker Michael Palardy. Corresponding cuts are not yet known.
Gilreath, a wideout and return man, has bounced around several NFL camps and made the Pittsburgh roster in 2012. His agent announced the signing on Twitter.
Vaughn, who played college ball at Oregon and San Mateo College, spent some time on the New York Jets practice squad last year. He announced his signing on Twitter.
Palardy went to Tennessee and was brought in primarily because he, like Raiders kicker Sebastian Janikowski, is left-footed. He’ll relieve Janikowski’s workload during training camp while maintaining a work routine for the holder. He too announced his signing on Twitter.