San Francisco 49ers running back Raheem Mostert isn’t going to have any more of a 2021 season, after suffering a season-ending knee injury during the Niners 41-33 win over Detroit on Sept. 12, after just seeing four snaps.

The former Purdue standout announced over Twitter that he will be having surgery to repair his knee.

Mostert was in line for the starting role as the 49ers running back, and looked solid in his 2 carries that covered 20 yards. But that’s where the season would end for Mostert, who played just eight games in 2020 while dealing with injuries.

An undrafted free agent out of Purdue in 2015, Mostert spent time with six different teams in less than two seasons before finding a permanent home with the 49ers. In November of 2016 he signed with San Francisco, spending time on the practice squad, and has been with the team ever since.

Mostert is set to become an unrestricted free agent at the end of the year.