The New England Patriots did not pull the trigger at the NFL trade deadline yesterday, which means that they will head into the second half of the season with the same core of players they already used from weeks one through seven. That being said, NFL rosters are obviously flexible constructs with injuries in particular impacting how a team builds and maintains its 53-man team and 10-man practice squad over the course of a season.
New players are added to those teams on a regular basis, and with the season already in full swing need to be brought up to speed as quickly as possible.