Morris may start the campaign as the 49ers' starting running back if Jerick McKinnon's knee injury is serious, Matt Maiocco of NBC Sports Bay Area reports.

After Saturday's team workout, coach Kyle Shanahan said that McKinnon suffered a non-contact knee injury, and an MRI has been ordered. If ligament damage is confirmed, McKinnon would be in line for an absence that could extend for the entire season. Morris has experience working with Shanahan, who was his offensive coordinator in Washington the first two years of his career. Those campaigns were the most productive of Morris' career, with 1,000-plus rushing yards in both and 20 total touchdowns on the ground. He'd be contained to work on obvious run downs due to the presence of change-of-pace back Matt Breida.