San Francisco 49ers

49ers look ahead: Cornerbacks have potential but are unproven

San Francisco 49ers defensive backs L.J. McCray (31), Keith Reaser (27) and Jaquiski Tartt (29) during an NFL football mini-camp in Santa Clara, Calif., Wednesday, June 10, 2015.
San Francisco 49ers defensive backs L.J. McCray (31), Keith Reaser (27) and Jaquiski Tartt (29) during an NFL football mini-camp in Santa Clara, Calif., Wednesday, June 10, 2015. AP

Over the last 10 days, I’ve been ranking the 49ers position groups from strongest to weakest. Next up ...


Recap: Over the last few seasons the 49ers have changed starting cornerbacks with every calendar year. The tandem of Carlos Rogers and Tarell Brown gave way to Chris Culliver and Perrish Cox. That duo will be replaced by ... ? Veterans Tramaine Brock and Shareece Wright are the likely starters, but as last season showed, that can't be set in stone. Brock, after all, was slated as a starter but a toe injury in Week 1 limited him to only a handful of snaps on the season. Cox, who had had a strong training camp and preseason, replaced him and went on to have the best season of his career. He led the 49ers with five interceptions and was signed by Tennessee in free agency. While Cox started hot, it was Culliver (four interceptions) who was better as the season ended and he was farther removed from his 2013 ACL tear. He signed with Washington in free agency. Rookie Dontae Johnson, Leon McFadden and Marcus Cromartie also saw action at the position with Johnson starting the last three games. Rookie Kenneth Acker had a solid preseason but injured his foot and was placed on injured reserve. Chris Cook also looked strong in the preseason. He seemed primed for a role on defense just as he suffered a season-ending hamstring tear in Week 7.

Outlook: The 49ers have plenty of bodies at cornerback but no one who has proven himself at the position. Brock has looked outstanding at times, showing rare quickness and ball-hawking skills. But every time he seems ready to seize a starring role, he has gotten injured. There has been talk of Brock shadowing the opponent's top receiver this year as opposed to the cornerbacks sticking to one side of the field as in years past. The 49ers have confidence in Wright and see him excelling in their defense the way that castoffs like Rogers and Cox have in previous years. But he certainly did not excel in San Diego. Pro Football Focus ranked him in the bottom 10 among starting cornerbacks the last two seasons. The intrigue lies among three players going into their second seasons. The most physically gifted is Keith Reaser, a former track star whose rookie season was wiped away by ACL complications. Reaser played both on the outside and at the nickel spot in the spring. Johnson has the length that the 49ers like at the position and also is capable of matching up with the opponent's slot receiver. Acker will look to build upon last year's solid training camp and preseason. Cook, meanwhile, is the most physically imposing of the group and the most capable of playing the type of press coverage the Seahawks use. Considering his career began in Minnesota, he's also familiar with the slate of NFC North opponents on the 49ers' schedule this season.

Question marks: Will Jimmie Ward be the sole nickel cornerback as he was when he was healthy last season? Or will the 49ers use other players -- like Johnson or Reaser -- based on the matchup? ... Can Brock stay healthy? If the answer is, yes, he would be a heavy favorite to lead the 49ers in interceptions, something at which he has excelled in 49ers' practices.

Person of interest. That honor goes to Reaser. The 49ers consider him a third-round talent who fell to the fifth round due to injury concerns. Will he be the first injured draftee to excel for the 49ers?


49ers position ranking:

1. outside linebacker

2. safety

3. defensive line

4. running back

5. wide receiver

6. quarterback

7. tight end

8. inside linebacker

9. cornerback

10. coming Sunday

Matt Barrows: @mattbarrows, read more about the team at