Mostert suffered a knee injury during Week 1, and the 49ers felt the running back would miss about eight weeks. However, Mostert opted to have season-ending surgery instead, a decision that writer Tyler Dunne states "absolutely pissed the 49ers off."
"It isn't right," Mostert told Dunne. "And it's up to the player to step up and say, 'This isn't right. I don't think this is the best of my interest.' Sometimes, you don't get that with players. But, for me, that was my case. I knew exactly what I wanted. I knew exactly how I'd handle the situation. I knew exactly—coming off of rehab—what I needed to do in order to get back on the field."
Mostert added, "I moved on from the situation. I have the opportunity to see them."
On Monday, head coach Kyle Shanahan was asked about Mostert's comments and if there is any truth to the criticisms.
"There was all different types of opinions during that from where we were at—Raheem, his agent, everybody," Shanahan told reporters on a conference call. "Just like there always is, there's first opinions, second opinions. So yeah, there's always different opinions on those things."
The 49ers and Dolphins, the two leaders in their respective divisions, will clash on Sunday afternoon at Levi's Stadium.