Stevenson (undisclosed) left the field as his teammates prepared for final sprints during Tuesday's practice, Andrew Callahan of the Boston Herald reports.
Per Callahan, Stevenson, who was a full participant right up until the sprints, did not speak with the media afterward, as he was scheduled to, so it's unclear what led to his early exit. Look for added context regarding the running back status to surface once the Patriots hold their next practice.