He’ll play a pivotal role one way or another.

Over the previous two years, the San Francisco 49ers had to ask themselves some serious questions about their linebacker depth, particularly entering 2024 when veteran Dre Greenlaw was coming off a torn Achilles suffered in the Super Bowl the previous February. And then again when Greenlaw departed via free agency to the Denver Broncos in 2025.

While the De’Vondre Campbell experiment turned out to be a disaster, the Niners felt good about a couple of reserve options being bumped up the depth chart: Dee Winters and Tatum Bethune. It certainly appeared as if both would help shore up Greenlaw’s absence, and those efforts were on full display throughout last season.

But things have changed since then. A lot.

Bethune, the seventh-round pickup by San Francisco from the 2024 NFL Draft out of Florida State, might be viewed as one of the key components entering 2026 despite San Francisco’s reunification with Greenlaw. The 49ers cleared the way for the former to assume a prominent LB3 role on the depth chart by shipping Winters off to the Dallas Cowboys last April.

And, despite already having second-year pro Nick Martin and adding rookie Jaden Dugger via the draft, Bethune might not exactly be competing with those two directly for the depth chart pecking order.

Despite some promising flashes last year, 2026 might be the year in which Bethune fully emerges to the surface.

Tatum Bethune should play a significant role for 49ers defense in 2026

There’s little doubt what th Niners envision atop their linebacking depth chart this year: All-Pro Fred Warner leading the way with Greenlaw right behind him—a second edition of the pairing that existed between 2019 and 2023.

It’s fluid after that, though. Yet the need for a quality third off-ball backer will be vital, particularly knowing Greenlaw’s extensive injury history.

While Bethune might not expect to see eight starts like he did a year ago, that rotational third-linebacker role has been pivotal for San Francisco in previous years, helping develop fringe backers like Demetrius Flannigan-Fowles and Azeez Al-Shaair into more prominent players. Plus, with Bethune already established as a quality run stopper, there’s a great chance he’ll see some serious field time despite an at-best No. 3 spot on the depth chart.

As for Martin and Dugger, those two are less known for their off-ball skills and figure to be more of a walk-down linebacker in coordinator Raheem Morris’ five-man fronts; an extra defender to help set the edge while creating pressure in passing situations.

Of course, things are a bit more fluid than just that kind of use, but it’s worth pointing out Bethune should be the primary backup and rotation option for Warner and Greenlaw, while Martin and Dugger are competing for a different kind of role.

Based on how well he performed said duties last season despite several injuries, it already seems as if Bethune will be ticketed to that crucial LB3 role on the depth chart.

And if it goes well, Bethune’s own career should emerge nicely out of the Warner and Greenlaw shadows.