[cincinnati chili]

I'm not sure what Cuban closer you're talking about, but here's the rule:

If a Cuban defects to the U.S, a U.S. territory (incl. Puerto Rico), or Canada, he would have to pass through the June draft before any team can sign him.

If a Cuban defects anywhere to else in the world (e.g. Costa Rica, Dominican Repub), he is a free agent. That's why guys like Contreras take pains to seek asylum in other countries. You make more money when you can negotiate with 30 teams than when you can negotiate with one.