SANTA CLARA, Calif. - The 49ers kept five cornerbacks on their 53-man roster they finalized over the weekend. But they remain unsure of who will start opposite Tramaine Brock in Monday night's season opener against the Vikings, if Brock is healthy enough to play.
Second-year players Keith Reaser and Kenneth Acker are the favorites despite missing all of last season with injuries. Dontae Johnson is also in the mix, head coach Jim Tomsula said Tuesday. Three players, all drafted in 2014, are fighting for the chance to start.
"You will see throughout the year, matchup-wise, you'll see us matching up the way we need to match up with those guys, between those three. But Acker has really come on and done a great job," Tomsula said.
Brock is dealing with a hamstring injury that prevented him from suiting up for the final preseason game against the Chargers. Brock played in just three games last season because of toe, ankle and hamstring injuries. But Tomsula indicated his top corner should be good to go against Minnesota.
"I think we've got that to where we wanted it to be coming into the season," Tomsula said. "I don't think he's going to show up on any of your injury reports."
Quietly, Acker has put together a second consecutive strong preseason after making his pro debut last year before ending up season-ending injured reserve with a stress fracture in his foot. This preseason he allowed just three receptions on eight targets for a 7.8 passer rating, according to Pro Football Focus, including an interception against Denver in the third exhibition game.
Reaser played 65 snaps in the preseason, and allowed eight catches on 11 targets, per PFF. He made his professional debut in the opener against Houston after sitting out all of last year recovering from an ACL tear sustained at Florida Atlantic. Reaser might be the fastest cornerback on the roster, which has leant itself well toward practicing in the slot, where Brock is likely to be the first option.
Receiver Torrey Smith, who has gone against all the 49ers cornerbacks in training camp, thought they played well in their first extended action.
"I didn't even know they missed all that time (with injuries)," Smith said. "I think it says a lot about what they did rehab-wise to get where they are. They're doing a great job, both young, both very talented.
"I think they're both very smooth. That's probably the thing that stands out most about them. And they're very confident, which probably means more than anything, especially at their position, because there's going to be some times where receivers are going to make some plays and they're going to have to be able to bounce back. And they're new, so quarterbacks might try to pick on them, see where they stand. They're going to have to be able to stand up to that. I think they'll be ready for it."
Given Johnson's solid play as a rookie last season, it's a surprise he isn't being considered as highly for the starting job as Acker and Reaser. Going against mostly reserves this preseason, Johnson allowed just four catches on 14 targets, according to PFF, with three pass break ups and an interception against the Cowboys.
Five-year veteran Shareece Wright, who started 27 games for the Chargers the last two seasons, started in the preseason opener, but has been working with the reserves ever since.
Chris Biderman is the Editor-in-Chief of Niners Digest and covers the 49ers from their headquarters in Santa Clara. Chris has been writing about the team since the spring of 2013. The Ohio State alum received his Journalism degree in 2011 and has been working in sports media since 2008. Chris, a Santa Rosa, Calif. native, is also a contributor to the Associated Press covering sports throughout the Bay Area. You can follow Chris on Twitter here.
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