I think that in the MLB, teams cannot be promoted nor relegated - so teams from say Cuba, Mexico or Puerto rico are playing Minor league and work as feeder teams to MLB teams. Not sure why MLB is being discussed in a Spurs forum at all, but that's my understanding of it.
Each MLB has about 3 minor league teams of their own. A, AA, AAA
Half of Central America plays MLB it seems.
I would like to see Walker back. A little speed in the back would be nice.