San Francisco 49ers cornerback Tramaine Brock is a question mark for Sunday's game, as the beat writers are reporting an MRI revealed a sprained toe. His status is unknown, and I imagine we will see him listed as questionable at best when Sunday's injury report rolls around.
Brock was injured in the first quarter of Sunday's win over the Dallas Cowboys. However, that was likely due to Jimmie Ward's injury. The 49ers rookie defensive back reportedly suffered concussion-like symptoms. Perrish Cox and Dontae Johnson were already in the game, and with Chris Culliver out with a concussion, and Chris Cook inactive, it likely forced the 49ers hand with Brock.
Jim Harbaugh had no word on Ward or Culliver, but they will likely go through the NFL's concussion protocol. That takes several days, which means their respective statuses will probably not be known until Friday or Saturday.
That leaves the 49ers with Dontae Johnson, Perrish Cox, and Chris Cook as the only completely healthy cornerbacks on the 53-man roster. The 49ers also have second year defensive back Chance Casey on the practice squad. The 49ers have generally cleared players through the concussion protocol fairly quickly, but I don't think we can make any specific predictions yet for Culliver and Ward. But once we know more on those two, that will give us a better handle on the situation.