Tatum Bethune Injury: Diagnosed with high-ankle sprain

San Francisco head coach Kyle Shanahan said that Bethune suffered a right high-ankle sprain in Sunday's 41-22 win over the Cardinals and is expected to miss multiple weeks, David Lombardi of SFStandard.com reports.

Shanahan said that Curtis Robinson will be the next man up at middle linebacker for the 49ers, who are already without Fred Warner (ankle) for the rest of the season. Bethune had recorded double-digit tackles in five straight games prior to being injured in the first half versus Arizona. Though the 24-year-old linebacker looked poised to miss multiple games, Shanahan said that Bethune is expected to avoid a stint on injured reserve.