Since free agency started March 11, the San Francisco 49ers have re-signed Anquan Boldin and filled needs at safety and backup quarterback. But they haven't fully addressed their cornerback losses—cutting Carlos Rogers and not re-signing Tarell Brown.
Sure, they've re-signed Perrish Cox and Eric Wright, and they gave free-agent cornerback Chris Cook a one-year deal. But none of those three is a sure thing to earn the nickel cornerback role alongside Tramaine Brock and Chris Culliver.
San Francisco's biggest draft need is cornerback. The Niners don't have a bona fide No. 1 guy on the roster right now, and they have six of the first 100 picks of the 2014 NFL draft to find a future star.
Culliver is likely to fill Brown's role and start on the outside. This means the Niners could use a slot cornerback who excels in man coverage, though I'm sure they wouldn't mind finding the next Darrelle Revis on the outside and shifting Brock or Culliver to the slot. In general, the 49ers are always after defensive backs who are sure tacklers.
The following five cornerbacks—ranked in order of Matt Miller's post-combine draft big board—have the tools to contribute to San Francisco's defense.
Height, weight and 40-yard dash times via NFL.com. Prospect rankings via Miller's big board.