My comment came from the fact that I am working in South America and it was pretty amazing the coverage that papers and tv stations gave to the draws in the last sixteen.
Yes, countries like Mexico, Cuba, the Dominican Republic, Panama, Venezuela have their own national baseball leagues and I believe they play a regional tournament with their best teams, but this is a pretty small sample of Latin American countries. On the other hand, you have the Libertadores Cup with teams from all around South America (except for the small three countries north of Brazil) and Mexico (teams from other countries in Central America don't play but that is not because soccer is not popular, other reasons). You also have continental cups in Africa and Asia. This is pretty difficult to find in other sports, except maybe in tennis with the Davis Cup. But anyway, I wasn't trying to argue that soccer is more popular than any of the four main sports in the US. It is just that it is pretty nice how countries all over the world follow the European Champions League, something that doesn't happen with other sports.