Protective Cups and Testicular Injury

A debate has developed in my youth football program regarding the use of protective cups. Although, an athletic supporter and protective cup is mandatory per league rule, some coaches down play the importance of a protective cup by saying the cups use is mandatory, however, they will not check (via "knock-knock drills) nor will they ask a player if he is wearing a protective cup.

These coaches are of the opinion that a more serious injury can occur if a cup is used improperly. As an adult male, I do not understand how a cup can be worn improperly---if it is it must be very uncomfortable.

What is the position of your organizations. Is there any credible evidence that the use of a protective cup caused an injury.

Any feedback would be appreciated. Thanks for your advise and input.