According to this article:
NFL to crack down on teams using fake injuries

The NFL is going to use its resources to try to identify gamesmanship issues. That's well and good for them.

From a JV and HS level that I and most folks call at, the options are fewer. Even if you notice a pattern, it's not possible to prove. While the rules do permit the referree to take whatever action he deems necessary to correct unsporting acts, you first have to KNOW that it is an unsporting act and not a genuine injury. Couple this with a "boy who cries wolf" problem--the first two or three times a kid goes down he could be faking, but if you then act on the wrong one-the genuine injury-you've got egg in your face.

The only recourse that becomes available to me is to record all the conditions that I can regarding a series of apparent fake injuries, and report the situation to the association and state offices after the fact. They can review the tape, interview people, and award forfeits or other action as needed. On the field, unless I can PROVE that the kid is faking (practically impossible, as I am not a P.I. or a doctor), the only thing I can do is call the officials' timeout and take notes.

Thanks for the thoughtful responses in this thread.

Officials on the field should not be put in a position of trying to figure out whether an injury is being faked or not. On-field responsibilities just don't allow it. In my mind that just leaves the only recourse as making players sit for longer than one play if they have to be attended to on the field.

Administering that rule change would certainly be better than trying to read intent on the field. That job should be left to conference commissioners if evidence piles up game after game. If it does, head coaches need to be suspended for unethical coaching practices.

The only possible way I could ever tell if a player was faking an injury would be if I actually heard a coach say something like "someone fall down" or heard a player, when being talked to by the team attendant, say something like "Everything's fine, I just wanted to slow them down".

And even then, I'm not sure there's much I could do about it. Could probably throw a USC flag under the "unfair acts" rule, but that's about it.