Bethune (ankle) is not participating in Wednesday's practice, Jennifer Lee Chan of NBC Sports Bay Area reports.
Bethune has not played since Week 11 due to a high ankle sprain, and even now coming off a bye week, he isn't ready to take the practice field. The starting linebacker will have two more opportunities to get back on the field as at least a limited participant ahead of Sunday's game against the Titans, but if Bethune is unable to play Week 15, Curtis Robinson will handle an expanded role on defense again.