The San Francisco 49ers head into Sunday Night Football with significant injury issues. One such area of concern is in the secondary. That injury list includes Tramaine Brock, Jimmie Ward, Chris Culliver, and Chris Cook. Brock (toe), Culliver (shoulder/hamstring), and Ward (quadricep) are questionable, while Cook (quadricep) is probable.

Ward and Brock are the bigger question marks of this group. Ward's quadricep strain was reported by Adam Caplan as being more of a week-to-week injury. Jim Harbaugh said it was a question mark and would just heal when it heals. Brock is wrapping up rehab on his turf toe, and got in limited practice sessions this week. I still think he returns after the bye, but we'll see.

Culliver was on the injury report with a shoulder injury, but he was a DNP in practice on Friday with what Matt Barrows said was a hamstring strain. I suspect he plays, but who knows if the hamstring will be an issue.

Ward seems the most likely to to sit on Sunday, which means the team will need to make some changes in their secondary. Perrish Cox would seemingly move into the slot when the 49ers are in their nickel and dime packages. That would open a spot for Chris Cook and/or Dontae Johnson. Cook seemed to be the first off the bench last week, but Johnson ended up with more defensive snaps than Cook.

Speaking of the dime, I still think we see the 49ers employ a sizable amount of their dime defense. The 49ers will face a whole lot of Broncos pass catchers, but also, the dime provides them a chance to stick with one inside linebacker in the face of questionable depth. Patrick Willis will not play, which moves Chris Borland into the starting lineup in their base and nickel defenses.

David Neumann talked about going with more dime to essentially dare the Broncos to run more. That would test the defensive backs, but it would potentially help contain Peyton Manning's arm, at least a little bit. If they go with the dime, and do not have Tramaine Brock back in the lineup, it would mean plenty of both Chris Cook and Dontae Johnson. If Brock is back in the lineup, then it seems like it might be more Johnson in the slot over Cook.

I'm not entirely sure how it will play out, in part because I think both have actually played well in limited appearances. Johnson likely has more of a future with the 49ers, but with both playing fairly well, it will be interesting to see what kind of rotation the 49ers employ on Sunday.