Their pass defenders simply can't secure the football when it does come their way.

SANTA CLARA San Francisco 49ers Customized Jerseys , Calif. (AP) — Opportunity is slipping through San Francisco's young defensive backs' hands.Through 12 games, the 49ers have just two interceptions — the fewest in the NFL — and it isn't always for lack of being in position to make big plays. "Every game it seems like the ball's on the ground or we're missing an opportunity," 49ers defensive coordinator Robert Saleh said. "They are going to come in bunches, but it's baffling to me that we haven't been able to get (more interceptions)." Losing the turnover battle goes a long way toward explaining the 49ers' 2-10 record as they prepare to host the Denver Broncos on Sunday.San Francisco's minus-20 turnover margin is the worst in the league. The 49ers have turned the ball over 25 times but generated just five takeaways themselves.Part of that, at least in terms of pass defense, can fairly be attributed to the youth and inexperience in the secondary.Former All-Pro cornerback Richard Sherman lends veteran wisdom in his first year with the team. But second-year cornerback Ahkello Witherspoon has been picked on by opposing quarterbacks on numerous occasions this season.Witherspoon also failed to haul in a potential interception on a slant pass that he defended well last week against Seattle.Due to injuries, the 49ers are expected to start a pair of rookies at the safety positions Sunday in D.J. Reed and Marcell Harris, who have a combined 15 games and two starts of NFL experience between them.Reed, at free safety, is replacing the injured Adrian Colbert, who is only in his second season himself.Sherman said young defensive backs often get themselves in position to make plays but lose concentration on the most important part – wrapping up the football for an interception."The old saying was the reason they play ‘DB' is because they can't catch San Francisco 49ers T-Shirts , but I don't think that's as true anymore," Sherman said. "Some of it is just guys panicking. Guys getting big eyes and seeing the end zone and seeing space in front of them and not going through the last second of looking the ball in."But Sherman, a four-time Pro Bowl player in his eighth season, hasn't helped in this department either. He entered the season with 32 career interceptions, most among all active players since 2011, but has yet to record one in 2018.In Sherman's defense, he isn't getting that many opportunities since opponents are choosing to target Witherspoon in coverage more.Never has Sherman recorded fewer than two interceptions in a season.Is he aware of that stat?"Yeah, (but) the ball will get where it gets," he replied.Denver quarterback Case Keenum threw 10 interceptions through the Broncos' first eight games, but he hasn't been picked off a single time over the past four.NOTES: Receiver Marquise Goodwin practiced for the second day in a row and looks poised to return to the lineup after missing the past two games while being away from the team for personal reasons. With fellow starting receiver Pierre Garcon (knee) not having practiced Thursday, there seems a decent chance that rookie Dante Pettis draws the start opposite Goodwin against Denver. Pettis is coming off a breakout game against Seattle (5 catches https://www.49ersfanshop.com/hats , 129 yards, 2 TD's). … Safety Antone Exum (knee), cornerback K'Waun Williams (knee) and linebacker Malcolm Smith (Achilles) were limited in Thursday's workout. Good morning folks. It’s an extremely busy week for me, as the combination of work (end-of-the-calendar-year stuff) and classes (exams week) are eating up much of my existence, and so I’ll try to keep it short. As you’ve probably heard, our founder and long-time editor Fooch has designed and accepted a new position within the SBN mothership, and his days as the fearless leader here are numbered. It’s certainly a big loss to the Niners Nation site, but perhaps an even bigger loss to the Niners Nation community as a whole - his ability to stay level-headed and neutral on virtually any topic has led to over a decade of healthy, knowledge-building discussion around our San Francisco 49ers as a team and as an organization. He’ll be greatly missed once he departs at the conclusion of the season.Anyway, after a few weeks of having a relatively clean injury report, the volume of players listed is beginning to grow again. Dekoda Watson has been officially placed on IR and 2017 draftee Pita Taumoepenu has been called up to replace his spot. Often injured RB Matt Breida and S Jaquiski Tartt did not practice on Wednesday San Francisco 49ers Hoodie , which clouds the likelihood of the former playing on Sunday, and lines up with the latter’s being ruled out. DB DJ Reed has returned to full practice, luckily at a time when Tartt is out and backup Antone Exum is limited in practice - suffice it to say, the safety position is on shaky ground. Pierre Garcon remains limited with a knee injury that has been nagging him for most of the season, although the 49ers get Marquise Goodwin back, after a two week absence due to family issues. The offensive line is represented by Weston Richburg and Laken Tomlinson, both being limited in practice on Wednesday.Week 14 injury report | Chan, NBC Sports Bay Area | Madson, NinerswireRB Jeff Wilson Jr. made a great first impression | Branch, SF Chronicle | Almquist, KNBR | Biderman Roger Craig Jersey , Sac BeeLB Pita Taumoepenu promoted from PS | Maiocco, NBC Sports Bay Area | Madson, Ninerswire49ers need to tailor defense to their players | Jeff Garcia, NBC Sports Bay AreaMullens worthy of a fifth start | Maiocco, NBC Sports Bay Area49ers to sign LS Colin Holba | Almquist, KNBR | Madson, NinerswireKyle Shanahan: Effective pass rush can hide a lot | KNBR Staff | Biderman, Sac Bee | Madson, NinerswireLS Kyle Nelson’s PED suspension not his first | Madson, Ninerswire