Who knows the club side Fredua Koranteng Adu earns his living playing for these days?About 80 percent of soccer enthusiasts do not know; the remaining 20 percent simply do not care.The answer is the Philadelphia Union of Major League Soccer.Adu pitched camp with the MLS outfit via Benfica, AS Monaco and the likes of Belenenses, Aris and Caykur Rizespor. At the age of 22, Adu is a veteran of the European game, having played in Portugal, France, Greece and Turkey. And like all veterans, he is nearing the twilight of his career.Adu was the quintessence of soccer prodigyhood. In early 2004, the D.C. United selected Adu with the top pick in the MLS draft. His four-year contract made him the highest-paid player in the league—at age 14. That is record may never be broken—at least not in Adu’s lifetime.This brings to mind a certain 15-year-old son of a factory worker who laced up for the Argentinos Juniors club of Buenos Aires in 1976; and of another 15-year-old who took the field to score for Brazilian club Santos in September 1956.The similarity between these three greatest soccer prodigies produced in the Americas is glaring—they had enormous potential to raise the world ...