Tuesday is a tough day for NFL teams as they must reduce their rosters from 90 to 53 players. The deadline is set for August 26 at 4:00 PM ET. It's difficult for teams to leave 37 players without a job; fortunately, each team can reinstate up to 16 players to the practice squad, either from their own 90-man roster or from waivers/free agency.
In the end, it's the business side of the sport, and if you don't convince your coaching staff you're a potential key player during OTAs, camp, and preseason, you will get cut—it's just that simple.