I would suggest not translating the phrase: any translation would bound to be as confusing as the original--if not more so.

Instead, add words to the text such as:

"The quarterback barked out signals that provided coded instructions as to what each player on the team was to do once the ball was snapped: i right flex z....etc."

Incorporating an explanation of the meaning of the signals in this way would be much more useful for an audience unfamiliar with American football. If the audience is familiar....then you don't need to explain, but can still leave the signals untranslated.

Suerte.