• 100 percent of Russian national team players play in Russia.
• 96 percent of players on England’s World Cup team play in England. The remaining slot on the roster is filled by Fraser Forster, who plays in Scotland (which fields its own national team).
• 87 percent of the Italian team’s players normally play in Italy
• 74 percent of players on the German team play in Germany.
• At the other end of the spectrum, Uruguay has no players on its national rosters who play at home. The national teams of the Ivory Coast, Ghana, and Bosnia and Herzegovina’s each have just one player—4 percent of their total roster—who regularly plays at home.
• Less than half the U.S. World Cup team—just 39 percent—plays on U.S. professional teams. Four play in England, and four play in Germany, the result of U.S. coach Jurgen Klinsmann’s explicit recruitment of German dual citizens.
• While U.S. professional leagues attract foreign talent in many high-level sports, the strength of football in other parts of the world leads to this reverse migration of talented American players abroad. Just 3 percent of World Cup players are employed by the U.S.’s Major League Soccer. 

Wow, the U.S.'s Major League Soccer is tiny compared with other leagues!