This is the worst possible news for Mostert, who will miss all of 2021 after playing in just eight games last season. The talented runner jumped around the league early in his career with stops in Miami, Baltimore, Cleveland, and Chicago before finding a more permanent home with San Francisco in 2016. Unfortunately, a series of injuries has kept him from ever really fulfilling his true potential as he's only been able to play in all 16 games in one of his seven seasons in the league. At 29 years old, it's hard to see a path for Mostert to regain much dynasty value after this latest injury. On a side note, our job is to bring you dynasty analysis. Mostert's family has received multiple terrible messages on social media and that's unacceptable. You follow us to get analysis and that's what we're providing.