Bethune logged six tackles (two solo), including 1.0 sacks, during Thursday night's preseason opener against the Titans.
Bethune participated on 39 snaps, logging 29 defensive plays over the course of the night. The linebacker played 48 percent of the 49ers' defensive snaps and sacked Will Levis on the Titans' 20-yard line in the third quarter. Bethune is set to be a second-string interior linebacker for the 2026 campaign behind Dre Greenlaw and Fred Warner.