Harris left Wednesday's practice early with an apparent injury and didn't return, Zack Cox of NESN.com reports.
Harris walked off without assistance while talking to training staff. Should he miss the team's final preseason game Friday versus the Raiders, Rhamondre Stevenson and Ty Montgomery would likely get most of the first-team snaps. All three took snaps with Mac Jones and the first-team offense in last week's exhibition win over Carolina, with Harris getting the start and the first carry.