Yahoo Sports reports: It was a stadium like any other, packed with American sports fans wearing their favorite team's jerseys and red-white-and-blue face paint, roaring as players took the field. The U.S. team's home opener in the World Cup against Paraguay on Friday brought tens of thousands of passionate soccer enthusiasts to the massive stadium near Los Angeles. Many fans said they grew up playing soccer in recreational leagues as young children, and well into high school and college.