It carries over to the practice field. And it's absolutely vital during the ball game. You might be surprised to hear how many different types of communication are going on during an NFL game. The interior linemen communicate with one another to adjust blocking assignments. A quarterback communicates audibles at the line of scrimmage.
Defensive players relay and repeat calls, then communicate to one another based on the adjustments.
We gave up a touchdown pass to Baltimore because of a communication problem. Meanwhile, there is also communication between coaches and players, and between coaches and coaches. There is another form of communication that takes place, and most people hardly notice it. I'm talking about wireless communication from the press box or the sideline to the quarterback on the field. For many years, NFL teams sent in plays either verbally, by running substitute players on and off the field, or with the use of hand signals.