You need more than great athletes to compete at this level.

You need players that have essentially been raised with the ball at their feet. Taking a freak athlete at the age of 15 and trying to make him a soccer player just won’t cut it in international competitions. This is a common misperception of Americans who don’t understand the game - the current US team is likely as ‘athletic’ as any other team in the World Cup. What they lack are close-in ball handling skills, vision, and touch. Those are skills developed from a very early age and perfected by playing constantly against high quality opponents. I read a statement from one of Spain’s youth system coaches (I believe Barca, but could be wrong) that a kid has to have those skills by the age of six, or they won’t consider him for the youth academy. That’s not athleticism, that’s just pure skill.