49ers RB Raheem Mostert to have season-ending knee surgery

San Francisco 49ers running back Raheem Mostert announced on Tuesday that instead of missing just eight weeks with a knee injury, he'll be missing the rest of the 2021 NFL season.

Mostert released a statement on Twitter, explaining that he decided to undergo surgery to fix the issue so he can be completely healthy for next season.

Faithful,

After consulting with multiple doctors and weighing my options, I will be having season-ending surgery to repair my knee.

This gives me, without a doubt in my mind, the best possibility at coming back 110%. I have ALWAYS come back stronger and I will this time too! I have faith in myself, my doctors, my support system, my team, and God. He makes no mistakes!

I'm gutted. This sucks! This is obviously not what I worked so hard for I wish more than anything I could be out there on the field with my brothers!

Thank you for your support in our decision. I'M FAR FROM DONE!

— Mosterati

Mostert had just two carries in Sunday's game against the Detroit Lions before leaving with a knee cartilage injury. Head coach Kyle Shanahan said on Monday that Mostert had chipped the cartilage in his knee and would miss eight weeks, but after having conversations with his doctors, he decided that surgery was his best option. NFL Network's Tom Pelissero spoke with Mostert's agent, who said that reparative surgery has a six-month recovery timeline.

Mostert went undrafted in 2015 and spent the first few years of his career going from practice squad to practice squad. He hooked up with the Niners in late 2016, which is when his career began to take off. However, he just couldn't stay on the field. He finished the 2017 and 2018 seasons on injured reserve, but managed to sign a three-year contract extension with the Niners. He was able to stay healthy in 2019, but spent the majority of the 2020 season on injured reserve with a high ankle sprain.

Now Mostert will miss the entire 2021 season with another injury. To help fill the hole he's leaving, the Niners have reportedly signed running back Kerryon Johnson to the practice squad.