DuBose suffered a shoulder injury during Buffalo's practice Wednesday, Alaina Getzenberg of ESPN.com reports.
DuBose was carted off the field after falling on his shoulder during a drill, leaving his status up in the air for the Saturday's preseason game versus the Buccaneers. The 24-year-old had just signed with the Bills on Tuesday, and it's currently unclear how long he'll be sidelined.