On Monday, Kyle Shanahan delivered the news that Emmanuel Moseley has a high ankle sprain and will be out for several weeks.
Josh Norman and Dontae Johnson are the veterans remaining in the position group along with slot corner K’Waun Williams, but the 49ers need their rookies to step up. After playing only nine defensive snaps in the 49ers' 30-23 loss in Seattle, the defense tried a few different combinations.
Norman played nearly every defensive snap (70) but the 49ers gave Deommodore Lenoir a chance with 25 defensive snaps after Moseley left the game. The rookie allowed catches on all three of his targets for 39 yards and one touchdown. The Oregon rookie also was called for defensive pass interference and the ensuing play was a touchdown by the Seahawks.
In the second half of the game, the 49ers called on Johnson to play opposite of Norman. The 49ers' fourth-round draft pick from 2014 allowed three catches on all three targets but recovered a fumble forced by Azeez Al-Shaair, which prevented a Seattle score.
Shanahan didn’t seem too confident in any of his options when he spoke to the media via conference call.
“We'll see how the week plays out,” Shanahan said. “We’re obviously struggling in that area. Now losing E-Man definitely doesn't make it easier, but we're going to keep having the young guys compete. Hopefully they can get more and more ready. D-Mo did a couple good things in the game, but then struggled on some things also.”
Ambry Thomas, who was a third-round pick for the 49ers this season, did not see any time on the field on defense but did play 24 special teams snaps in Seattle. The rookie only has played 20 defensive snaps this season but nearly 100 on special teams, at times even serving as a kick returner.
“I’m happy with Ambry and how he played on special teams,” Shanahan said. “I thought it was his best game by far on special teams, having three tackles on it and doing the right thing on those. And hopefully those two can up their game up and push Dontae and Norman a little bit. But those are the guys that we’ve got.”
Thomas has not yet reached the level the 49ers had expected of him coming out of college, but sitting out of his final season at Michigan could be an explanation. Shanahan believes the young defensive back has been making progress and could start to compete for an opportunity.
“Whether it was the year off, I'm not sure,” Shanahan said. “Not being able to do much in OTAs, I thought Ambry was way behind the eight-ball in training camp. It got him off to a real slow start, D-Mo was ahead of him, back then.
“I think it's evened out. I think Ambry has really turned it on here in practice this last month or so. He’s been getting better each week and he's definitely got himself a chance to not only push D-Mo but to push the two starters out there too now.”
The rookies could have a chance to prove their mettle this week as the team prepares for Joe Burrow and the Cincinnati Bengals. The second-year quarterback had his third 300-yard performance of the season in the Bengals' loss to the Los Angeles Chargers in Week 13.