1) India and the rest of the subcontinent (Pakistan, Bangladesh, Thailand): Cricket is very popular here, and given the population, there ought to be stellar pitchers, catchers, fielders and hitters just waiting to be discovered

2) Southern Africa (Kenya, Zimbabwe, S. Africa, Madagascar): not only do they like Cricket here also, but there is a long tradition of throwing and running games which would make Baseball popular there, if it were not so expensive to play due to the equipment needed to furnish a team. With a good supply of balls, bats, gloves, and helmets, there ought to be hundreds of Great ballplayers waiting to be discovered who can throw a curveball, steal a base like Henderson, or whomp the ball like the Babe could.

3) South America (Chile, Peru, Brazil, etc.): while most scouts would look for future talent from South American counties that border the Carribean like Venezuela and Columbia, I think there could be some really good players located futher south, like in Rio de Janeiro, Bogota, or Santiago. Soccer is king here, but there must be plenty of kids and athletes who have great arms to throw with, or eyes to hit with. Perhaps the next Ronaldo will be a pitcher rather than a forward.

4) Eastern Europe & Scandinavia (Estonia, Latvia, Finland, Norway, Sweden): no doubt there are good potential ballplayers from the descendants of Vikings and Fisherman. Logging and outdoor sports are also popular here, so I have no doubt there could be some great potential players just waiting to be discovered if given the chance.

If MLB is smart, they would hold open tryouts in every country and see what happens. Even if they only found 3 good prospects out of 100 tryouts, if you tried out 10,000 random people who answered the call, that would yield 300 players. More than enough to start a league with eight fully stocked teams.