They already achieved their cap compliance 51 players on opening day of the league new year.
They, theoretically, can now be $50mil over until opening day. On opening day, the 53 man roster needs to be in compliance... That rookie pool is just their slotted contract. Predetermined by the pick in which they were taken. Only the 1st round pick has slotted guaranteed money. The remainder. If they don't make the team, or land on the PS. That contract changes to ps wages. Or prorated portion if they get cut.