The 49ers told beat reporters that star left tackle Trent Williams left Friday’s practice and headed into the locker room with an apparent back issue. Williams didn’t practice Friday, and we’ll see how that impacts his ability to play Sunday against a Miami Dolphins defense with two quality edge rushers in Jaelan Phillips and Bradley Chubb.
Head coach Kyle Shanahan will speak later Friday afternoon. Colton McKivitz or Jaylon Moore would step in for the All-Pro if Williams cannot play. The 49ers' roster is deep and can afford to miss a player or two, but Williams isn’t among one them.