Four teams are still alive in the postseason, but the other 28 are still working and preparing for the new league year that will start in March.
In the offseason, the NFL allows for team rosters to balloon up to 90 players from the 53 during the season, and practice squad players are eligible to be signed to reserve/future contracts which would add them to that roster for the spring and summer.
Miami signed seven practice squad players to the 90-man roster, but they let these 10 contracts expire: