Samuel did not play in Thursday night's preseason opener against the Titans.
Samuel joined Brock Purdy, Christian McCaffrey (undisclosed), Mike Evans (quadriceps) and a host of other injured Niners in street clothes against Tennessee. Samuel is 30 years old and just signed with the team two weeks ago. He's expected to push Christian Kirk (calf) and rookie De'Zhaun Stribling for targets alongside Evans this season.