SANTA CLARA, Calif. - Expect a platoon at nickel corner for the 49ers' fourth-ranked passing defense going forward.
With rookie defensive back Jimmie Ward done for the year with a foot injury, defensive coordinator Vic Fangio said he expects the team to use multiple players in Ward's stead.
Fourth-round pick Dontae Johnson got the first crack Sunday against the Giants. A few things factored into that decision, Fangio said, including the match up.
"We’ll analyze that every week and feel like where’s the best place for him to play, factoring in where’s the best place for (Perrish) Cox to play too. So it’s interchangeable," said Fangio.
With New York's talented wideout Odell Beckham Jr. spending most of his time lined up on the outside, Fangio elected to keep the veteran Cox in the same left corner role he's been in for most of the season since taking over for Tramaine Brock in the opener.
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Johnson, 22, was a surprise candidate to play the slot position after spending the majority of training camp working on the outside. The 6-foot-2 rookie doesn't have the typical build for the slot. The position is more closely associated with shorter players that excel in small spaces.
"(I) Just thought that it was the best way for us to play with the guys that we had left available," Fangio said. "...We just thought that gave us the best chance, the best combination of guys, even though Cox could have gone inside and Dontae could have gone outside."
Cox was the team's backup nickel behind departed veteran Carlos Rogers last season and played in the slot in the first two playoff games when Rogers was shelved with a hamstring injury. He played well in those wins over Green Bay and Carolina, and likely would have been pushed inside if Brock had been 100 percent last week. But Brock missed Sunday's game with a hamstring injury, and has not practiced this week.
"Of course the little guys are going to an advantage over me. At the end of the day, I play DB, I play corner. You have to have that quick twitch. I feel like I have it," Johnson said.
Johnson allowed three catches on four targets in coverage Sunday, but made one of the game's most important plays when he knocked away Eli Manning's pass to Preston Parker at the goal line that was picked off by Chris Borland.
"It was just one of those plays where, fourth down, pretty much if they score, it was going to put our offense in a tough situations and that was one thing we talked about during that whole drive," Johnson said. "...Thankfully Chris was there instead of an offensive player. After I had deflected it, I was a little nervous because it was up in the air for a while."
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Johnson's versatility, along with his length, was a trait that attracted the 49ers in the draft. He spent most of his collegiate career at NC State in the slot and has been a quick study, which allowed San Francisco to keep Cox on the outside against Beckham.
"That’s how I actually got on the field first, playing nickel my freshman year," said Johnson, a fourth-round pick.
Along with Borland and Aaron Lynch, Johnson is another member of general manager Trent Baalke's 2014 draft class that has contributed to the team's defense, which has remained strong despite the loss of six starters for various stretches.
Johnson has allowed nine catches on 17 targets and has three pass breakups. He returned his first-career interception for a touchdown in the final moments of Oct. 13's win over the Rams.
With Brock still dealing with the hamstring injury, it's likely Johnson will play a key role again this week against Washington. Head coach Jay Gruden uses three-receiver sets on more than 60 percent of his plays, according to Pro Football Focus.
With DeSean Jackson and Pierre Garcon getting the bulk of looks on the outside, Johnson could spend most of the day lined up in the slot against former Arizona Cardinal Andre Roberts, who signed a four-year, $16 million free-agent deal in the offseason.