How do NFL players know when to go in and out of the game?

Question

It seems like nowadays the running back or wide receivers go in and out almost every play. How do they know it’s their turn to go in or come out

In: Other

Answer 1

Each player is typically a part of a “package”. These “packages” have names, for this example we’ll use Jumbo. When the play gets called, all the coaches hear it over the headsets and starts relaying that to the sideline “Jumbo! Jumbo!”. Same with the players in the field, the QB will know what package the play is a part of and relay that to the players in the field. How do players know which package they’re in? That’s usually determined during the practice week.