Since Venezuela is listed as a "country of concern", that means no entry.
(if they're going to make exceptions for something as trivial as sports, then those kinds of enforcement mechanisms have no teeth)
When you're talking about the age range 13-16 (and there's not robust data sharing between two countries), you're talking about about the potential for people to sneak in under fraudulent documents. (potentially even adults, as most aren't going to be able to definitively tell the difference between a 16 and a 19 year old in many cases)
This happened back in 2011 if you recall with the Ugandan team. Where it turned out that several them weren't actually in that age range, were older, and were using fraudulent birth certificates.
You have cases like this happening as well
He was arrested on felony forgery charges. School officials in Perrysburg said the circumstances surrounding the case were "highly unusual and deceptive."
www.nbcnews.com
A Venezuelan dude (who was 24) was posing as a 16 year old for over a year, with a phony birth certificate that was apparently believable enough that it fooled a judge and several school administrators over a 1 year period.