Mattison (ankle) won't practice Wednesday, Paul Gutierrez of ESPN.com reports.
Fellow running back Zamir White (quadricep) was also sidelined Wednesday, after both players were forced out of this past Sunday's loss to the Dolphins. Mattison's status warrants tracking as this Sunday's game against the Broncos approaches, but for the time being, the healthy running backs on the Raiders' active roster are Ameer Abdullah and Dylan Laube. Chris Collier and/or Sincere McCormick could be elevated from the practice squad to provide additional depth out of the backfield if one or both of Mattison and White aren't available Sunday.