Two cornerback jobs up for grabs as 49ers open camp

Dontae Johnson will be competing for one starting cornerback spot in San Francisco's secondary. Isaiah J. Downing-USA TODAY Sports

SANTA CLARA, Calif. -- The San Francisco 49ers will report for training camp July 27, with the first practice slated for the following day.

As we head toward the start of camp, we're previewing each position and the competitions that could ensue. Today we look at the secondary, where it appears three starting spots are locked up but one outside cornerback job and the nickel cornerback position figure to be up for grabs as training camp begins.

On the roster:

Cornerbacks -- Rashard Robinson, Keith Reaser, Dontae Johnson, Ahkello Witherspoon, K'Waun Williams, Will Redmond, Adrian Colbert, Prince Charles Iworah, Will Davis, Zach Franklin.

Safeties -- Eric Reid, Jimmie Ward, Jaquiski Tartt, Lorenzo Jerome, Don Jones, Chanceller James, Vinnie Sunseri.

Locked in: Robinson, Reaser, Witherspoon, Reid, Ward, Tartt.

Battles to watch: A solid 75 percent of the starting jobs in the secondary appear to be spoken for as the Niners start camp. Robinson is a lock to handle the No. 1 cornerback job after a strong spring in which he impressed all observers, and defensive coordinator Robert Saleh spoke highly of him repeatedly. Reid and Ward have transitioned to the strong and free safety spots, respectively, and also received high marks from Saleh. It would take a drastic change or injury to move any of those three from the starting lineup.

After that trio, though, there appears to be plenty of wiggle room.

First and foremost, the starting corner job opposite Robinson figures to be a three-way battle among Reaser, Johnson and Witherspoon. All three took reps with the first team in the spring though Reaser appeared to have a slight edge. He's the most technically sound of the group but probably fits the profile physically the least. Johnson looks the part but had some struggles in coverage and will need to produce more consistently to win the job.

In an ideal world, Witherspoon would emerge and stake his claim. At 6-foot-3, 190 pounds with long arms and strong ball skills, Witherspoon is the perfect fit physically. But he has a lot of questions to answer about his tackling ability. The Niners believe he is willing but he won't get a chance to fully prove that until preseason games. All three will probably win a job in some form, however.

The other heated competition in the secondary is for the nickel corner job. While Reaser has proved capable of handling that position and could again if he doesn't win the other starting job on the outside, the Niners have a pair of intriguing youngsters who figure to battle it out: Williams and Redmond. Williams had the lead in the spring but both will get opportunities in the coming weeks.

As for depth, Tartt would seem to have a good handle on the third safety slot but the Niners will likely carry a fourth. That could come down to Jerome and James -- undrafted rookies who both had some good moments in the spring. Sunseri can offer some experience and special-teams acumen and Jones can do the same.

At cornerback, much will depend on how many the Niners keep. Davis could be a solid depth piece given his experience and Colbert might be one of the most interesting players to watch in all of camp regardless of position. The seventh-round pick out of Miami can play both cornerback and safety. Although the Niners have used him at corner to this point, his versatility might be necessary for him to lock down a roster spot. If he can chip in on special teams, he could put himself in position to stick around on the active roster.