49ers defense focused on stopping the run

SANTA CLARA - Loss No. 1 of 14 last season previewed how historically terrible the 49ers run defense would be.

Remember when Fozzy Whittaker replaced an injured Jonathan Stewart and ran for 100 yards in that 46-27 loss at Carolina? Remember how that started a NFL-record streak of futility: the 49ers allowed a 100-yard rusher in seven consecutive games?

Game No. 1 this season should reveal a lot, too, and not just because it comes against the same opponent, the Panthers, on Sunday at Levi’s Stadium.

Quarterback Cam Newton is coming off rotator cuff surgery and threw just two passes all exhibition season, so the Panthers most definitely will run at the 49ers, primarily with Stewart’s power approach and Stanford star Christian McCaffrey’s play-making versatility.

But the 49ers, perhaps you’ve heard by now, are opening a new era under coach Kyle Shanahan and general manager John Lynch. Changes abound on their defense.

“It feel likes a young team overall but in a good way,” nose tackle Earl Mitchell said in training camp. “Everybody has a fresh start, from top to bottom. We have a young, fresh, new mindset.”

That’s not all that gives this new-look defense hope.

There is a new one-gap scheme that simplifies assignments. “I understand what I have and go play after the whistle,” linebacker NaVorro Bowman said. “In previous years, you had maybe two gaps you were responsible for, and had to check those two gaps and make sure you were playing off the guy in front of you.”

There are new run stoppers such as Mitchell, the first outside free agent signed by Lynch, along with first-round draft picks Solomon Thomas and Reuben Foster.

There are new roles for old run stoppers, specifically with Eric Reid moving closer to the line of scrimmage while a single-high safety (Jimmie Ward, if healthy) patrols the secondary.

There is a new coordinator, for the third year in a row, in Robert Saleh, whose first words to the media in April were: “Stopping the run is our No. 1 priority. The way we align, our demeanor, the responsibility of the defensive players - we will stop the run on this defense.”

Of course, no new defense is complete without new mottos: “EXTREME VIOLENCE!” and “All gas, no brakes!”

Remember how the old defense extremely allowed more rushing yards (165.9 per game) and more rushing touchdowns (25) than in any of the 49ers’ previous 70 seasons?

OK, enough about last year - except to note that Whittaker’s 100-yard output remains the only such one of his 55-game career.

The 49ers’ reconfigured defensive front will rely on sturdiness from Mitchell, Thomas, DeForest Buckner and Arik Armstead. (Gone are Quinton Dial, Mike Purcell and Glenn Dorsey.) Eli Harold, Tank Carradine, Elvis Dumervil and Aaron Lynch are key on the edge.

Bowman’s return from Achilles surgery is being enhanced by Foster’s eye-opening presence as a lightning-quick, ball-seeking phenom.

“He’s been a good partner,” Bowman said. “(Foster is) just trying to learn from me, with me relaying certain terms we have to get accomplished on the field. So far it’s been good.”

Perhaps the best Week 1 matchup is how Foster counteracts McCaffrey, and the 49ers can only hope it goes as well as when Foster contained Minnesota Vikings rookie Dalvin Cook in the third exhibition.

Bowman’s second comeback in three years from a leg injury looks on course, and while the one-gap scheme is new to ?him, Saleh thinks that matters little.

“God, the guy gets like 150 tackles in his sleep,” Saleh said of Bowman. “When you’re dealing with a guy like NaVorro, instinctually they find the ball, they make tackles, they get (pass breakups). It’s what they do.”

What the 49ers defense needs to do Sunday is debut in the dominant fashion that’s bred victorious season openers every year since 2011.