San Francisco 49ers

With offense hobbled, 49ers defense takes increased responsibility Sunday vs. Rams

The 49ers finally appear to have found the right formula amid their unbeaten start.

It starts with their new-look defense, which has made a strong case to be considered among the best in the NFL. It’s been complemented by the league’s most prolific rushing attack, averaging 200 yards per game, similar to the physical style imposed by the successful teams coached by Jim Harbaugh earlier this decade.

“It’s the easiest way to win when you play real good defense and you can run the ball,” Kyle Shanahan said following Monday’s 31-3 throttling of the Cleveland Browns. “It takes the pressure off a lot of people and doesn’t put you in a lot of risky situations, but also can help you get some easier (explosive plays) too.”

But there’s a problem. A few, in fact.

San Francisco found out since Monday’s victory it will be without fullback Kyle Juszczyk, one of the most important assets in the running game, and right tackle Mike McGlinchey, a foundational piece of the offense who was a first-round draft pick in 2018. The team has already been without six-time Pro Bowl left tackle Joe Staley the past two games with a broken fibula, and he isn’t expected back until late October, at the earliest.

The 49ers will start Justin Skule and Daniel Brunskill at left and right tackle, respectively, who entered the year as the de facto fourth and fifth options at tackle. That’s because Shon Coleman was expected to be the team’s primary backup “swing” tackle, but he fractured his ankle in the first preseason game and was lost for the year.

Defense ready to attack the ball

Which makes Sunday’s divisional showdown against the defending conference champion Los Angeles Rams all the more imposing for Shanahan’s offense.

Which means the 49ers’ defense might have to carry the water.

“We have to put more on our shoulders and try to get the offense good field position, try to get the ball a little more,” DeForest Buckner told The Bee. “That’s what we look for every game is attacking the ball and trying to get more opportunities for our offense to get back on the field, so. We just got to really hone in on our details and just attack the ball.”

The defense enters its first divisional game ranked fourth in scoring (14.2 points per game) and second in yardage (258 yards). It’s also first in opponents’ drives that end in turnovers (21.3 percent) and completion percentage (53.5).

But it hasn’t gone up against an offense like the Rams that’s been one of the best in the NFL over the past two seasons since wunderkind coach Sean McVay took over in 2017. The 49ers have gone up against the 15th, 25th, 29th and 22nd ranked offenses during their first four games, and against quarterbacks with no postseason victories to date.

The Rams have sputtered their past two games, losing to the Buccaneers and Seahawks. But they enter Sunday with extra rest after having their previous game Thursday night while San Francisco will be traveling down the California coast on a short week. Plus, at 3-2, the Rams have extra incentive to beat the division-leading 49ers to avoid falling three games behind in the loss column, which could make winning the division exceedingly difficult.

49ers tinker with defense

Defensively, the 49ers tinkered with their scheme in the offseason with stopping the Rams in mind.

Using “Wide 9” techniques more often means defensive ends set the edge against outside zone running schemes while more often matched up with tight ends. It also helps in dealing with play action, which the Rams have typically used as often as any offense in the league.

“It allows our defensive ends mainly to really convert to their pass rush on play-action passes a lot faster than we have in the past,” Buckner said. “(The last two years) you’d read pass and you’d kind of get pinned inside and you can’t really get into your rush. It allows our defensive ends, like you saw on (Richard Sherman’s) pick, it was a play-action pass, and Nick (Bosa) was one-on-one with the tight end. It’s a mismatch every time. And he got pressure on the quarterback, made Baker (Mayfield) make a bad decision and Sherm came up with it.”

Buckner is having another stellar season that’s mostly gone under the radar. He joined Khalil Mack as the NFL’s only players this season to have 15 tackles, three sacks, two forced fumbles and a fumble recovery. Buckner’s logged sacks in three consecutive games.

Bosa, of course, has been a transformative presence along the defensive line. The reigning conference defensive player of the week is already playing like one of the best in the NFL at his position just four games into his career.

The No. 2 draft selection has rightfully garnered the most headlines following his breakout performance in Monday’s showing against Cleveland. But the 49ers have received strong play at nearly every level of the defense, including from linebackers Fred Warner and Kwon Alexander, and even from second-year cornerback Emmanuel Moseley, who made his first career start Monday.

Moseley was thrust into the lineup because of the foot injury to Ahkello Witherspoon. He broke up a possible touchdown pass in the first half and had good coverage on Odell Beckham Jr. along the sideline while forcing an incompletion on a deep pass from Mayfield.

On the end zone play, Moseley saw Browns’ tight end Demetrius Harris running uncovered up the seam and made up for the gaffe in coverage by breaking on the play and tipping the pass away.

“That was straight instincts,” defensive coordinator Robert Saleh said. “It wasn’t exactly the way we’d draw it up on the fit, but just his overall instincts, which is why we have great confidence in him, nothing’s too big for him. He saw, triggered, reacted, (and) boom, pass breakup. He’s got the speed, athleticism, length to be able to do something like that.”