I would think actually its easier for Carmona to get a visa than Fabio because he is a youth national player. There are two categories 1 for For Internationally Recognized Individuals or Teams and a For Professional Athletes.
Brenner is capped by Brazilian youth national team and comes from a Serie A club, so its probably easier for him to qualify for the first category which should have less applicants.
You need two of these, which for Brenner he's played with Brazil and the sports media statement if it can be an article would have plenty for Brenner to slide through.
- Evidence of having participated to a significant extent in a prior season with a major United States sports league;
- Evidence of having participated in international competition with a national team;
- Evidence of having participated to a significant extent in a prior season for a U.S. college or university in intercollegiate competition;
- A written statement from an official of the governing body of the sport which details how you or your team is internationally recognized;
- A written statement from a member of the sports media or a recognized expert in the sport which details how you or your team is internationally recognized;
- Evidence that you or your team is ranked, if the sport has international rankings; or
- Evidence that you or your team has received a significant honor or award in the sport.