Barring any pre-game setbacks, Samuel will be on the field with his teammates against the Dolphins.
On Friday, Williams left the practice field after team warmups due to back spasms.
"I'm not too concerned about it," head coach Kyle Shanahan told reporters after Friday's practice. "I asked [offensive line coach] Chris [Foerster] if he was all right. He said, 'It's just big-guy problems.'"
According to NFL Network's Ian Rapoport, Williams should also be on the field with his teammates.
Meanwhile, the Dolphins are preparing to start Greg Little and Brandon Shell at their tackle positions, with right tackle Austin Jackson ruled out and Terron Armstead unlikely to play. Little, Shell, and the Miami offensive line will go up against Nick Bosa and a 49ers defensive line that is getting Arik Armstead back.
The other 49ers players who were listed as "questionable" against the Dolphins are guard Spencer Burford (ankle) and defensive end Charles Omenihu (knee). The teams will release their lists of inactive players about 90 minutes before kickoff.