defensive backs' hands.Through 12 games Bradley Chubb Broncos Jersey , the 49ers have just two interceptions 鈥?the fewest in the NFL 鈥?and it isn't always for lack of being in position to make big plays. Their pass defenders simply can't secure the football when it does come their way."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 Von Miller Jersey White , 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 Royce Freeman Jersey , 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, 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. Bears defensive coordinator Vic Fangio said last week that he had done “zero” work to prepare for an expected head coaching interview with the Dolphins and it turns out that his time was better spent on other pursuits.It was widely reported that Fangio would be interviewing with both the Broncos and Dolphins on Monday, but it turns out that Denver was the only team to actually set up a meeting. Per multiple reports, the Dolphins requested an interview with Fangio and did research on him before stopping short of scheduling a sitdown.Fangio is set to meet with the Broncos a day after the Bears’ season came to an end with a 16-15 home loss to the Eagles.The Dolphins have interviewed Patriots linebackers coach Brian Flores, Chiefs offensive coordinator Eric Bieniemy, Saints defensive coordinator Dennis Allen and Cowboys defensive backs coach/passing game coordinator Kris Richard. They are expected to interview their special teams coordinator Darren Rizzi this week.