49ers' Raheem Mostert to Undergo Surgery for Broken Arm Injury

San Francisco 49ers running back Raheem Mostert suffered a broken arm in Thursday's 34-3 win over the Oakland Raiders at Levi's Stadium, coach Kyle Shanahan confirmed to reporters after the game.
Shanahan later announced Mostert would undergo surgery Friday and be placed on injured reserve.
Mostert, 26, went down on a gruesome third-quarter play that saw his arm bend in the wrong direction. Multiple players took a knee while trainers tended to him, putting Mostert's arm in a brace before he was taken off the field.
Mostert rushed for 86 yards and a touchdown on seven carries before he exited. He had carved a solid role in recent weeks as a change-of-pace back, rushing for 50-plus yards in three of the last four games.
Injuries have overwhelmed the 49ers. Their original starter at running back, Jerick McKinnon, suffered a torn ACL in the preseason. Fill-in starter Matt Breida has dealt with an ankle injury, and the team lost quarterback Jimmy Garoppolo for the season to a torn ACL in Week 3.
Every time something positive happens for this team, another injury cancels it out. Mostert is just the latest example.