The frog at the bottom of the well

The offseason training schedule of the thirty-two NFL teams is largely similar, typically organizing both a spring training camp and a summer training camp.

The summer training camp is mandatory for all team members, where the team will train on tactics, conduct actual combat drills, and select the final fifty-three-man roster as well as an additional ten-man practice squad.

On the other hand, the spring training camp is voluntary and focuses on recovery training, physical fitness, and basic skills, with the emphasis on integrating rookies into the team.

This is also known as Rookie Training Camp. First, the team will seize these opportunities to give undrafted rookies a chance to fill the required positions; second, the team will test all rookies and, if they're not suitable, will dismiss them after the spring training camp ends. For those rookies who don't make it to the summer training camp, it's as if they never joined the team.