Douglas (shoulder) was spotted wearing a red non-contact jersey during Sunday's practice, Mike Reiss of ESPN.com reports.
The severity of the issue remains unclear, but Reiss speculates that the rookie wideout is dealing with a minor shoulder injury that occurred when he was tackled during New England's second preseason game, which was versus Green Bay. Douglas, a sixth-round pick, has been a "pleasant training camp surprise," per Chad Graff of The Athletic, and he could carve out a role in the Patriots' pass-catching corps before long.