The Raiders signed Martinez to their active roster from the practice squad Friday, Levi Damien of USA Today reports.
Martinez was signed to the practice squad as insurance after Denzel Perryman suffered a concussion, and while Perryman is trending towards being available for Week 5, the Raiders will add the veteran Martinez as increased depth anyways. Martinez suffered a season-ending torn ACL in Week 3 last year, but he appears to be healthy after signing with Las Vegas. Before his devastating knee injury, Martinez had recorded at least 140 tackles in four straight campaigns.