Black (groin) is listed as questionable for Sunday's game against the Dolphins, Cam Inman of The San Jose Mercury News reports.
Black made a surprise appearance on Thursday's practice report as limited due to a groin issue, and he wasn't able to do enough Friday to enter the weekend without a designation for Week 2 action. His status may not be confirmed until about 90 minutes before Sunday's 4:25 p.m. ET kickoff, but if Black is inhibited or sidelined, Jordan James would be the primary reserve RB behind starter Christian McCaffrey.