Ranking the top 15 USMNT U-21 prospects, from Europe to MLS

I'm old enough to remember the good old days. You know, back when an American or someone FIFA might one day allow to be categorized as American made an appearance in the Danish Superliga, and everyone in a very specific and strange subsection of the internet freaked out. "Could he be the left-back of the future?"

There once was a time when the names Mix Diskerud and Edgar Castillo meant something -- when their very personal choice of what country to represent seemed like it could materially affect the future success of the U.S. men's national team. If the words "Josh Gatt" mean anything to you, then you know exactly what era I'm talking about.

Today, however, there are young Americans not only playing but flourishing for many of the best teams in Europe. We saw it at the World Cup when the USMNT -- the second-youngest team in the tournament -- played England to a stalemate in the group stage and reached the round of 16. Almost every U.S. player was a pro in Europe. The hopes and dreams of American soccer no longer sit on the shoulders of one specific prospect: The USMNT pool has more good players, more young players, and more good, young players than ever before.

While the Christian Pulisic generation will still lead the way at the next World Cup and maybe even the one after that, things can change quickly on the international stage, and it's worth taking a look at the group coming up. Ahead of the USMNT's upcoming friendly against Slovenia, who are the best 21-and-under players in the current player pool? From the guys everyone knows about to the guys that, well, no one really knows about, here is a ranking of the top 15 American U-21 prospects.