SANTA CLARA, Calif. — When defensive captain Fred Warner went down with a devastating ankle injury, Levi’s Stadium fell silent. But in that silence, a new fire was lit — and it burns in Tatum Bethune, the second-year linebacker now stepping into the biggest role of his career.

Bethune’s task is monumental: replacing the heartbeat of the 49ers’ defense, a four-time All-Pro and one of the most respected voices in the locker room. Yet rather than shrink from the challenge, he’s embracing it with calm determination and unshakable self-belief.

“He’s the best in the league, probably a future Hall of Famer,” Bethune said of Warner. “Those are huge shoes to fill, and everyone knows it. But I’m not here to be Fred Warner — I’m here to be Tatum Bethune.”

Head coach Kyle Shanahan admitted that rewatching the loss to Tampa Bay was “hard at first” after Warner’s injury — but said his mood quickly changed: “When I watched the tape again, I felt inspired by the way Tatum played. It gave me hope for what’s ahead.”

A former seventh-round pick, Bethune has already shown flashes of what he can bring. He led the 49ers with 10 tackles against the Buccaneers and impressed the coaching staff with his poise and physicality.

General manager John Lynch praised Bethune’s leadership qualities early on: “He’s not a Combine warrior, but he plays like a true Niner — tough, smart, fearless. Everyone who’s coached him says the same thing: he commands the huddle.”

Bethune has followed Warner closely — from his film study habits to his nutrition and leadership style. He even gave up his favorite candy to improve his conditioning. “Fred’s been everything — a teacher, a brother, a leader,” Bethune said. “My goal is to make him proud and carry the standard he built.”

With Fred Warner sidelined for the rest of the season, the 49ers’ defense now runs through Tatum Bethune — a young, hungry leader ready to keep the Faithful believing and the fire burning in San Francisco.