U.S. national team midfielder Gio Reyna has the potential that will allow him to "play for one of the best five teams in the world", says one of his former coaches.

At just 18 years of age, the hot prospect is already an established performer in the Bundesliga with Borussia Dortmund and with the senior United States national team with nine caps to his name.

The sky would appear to be the limit for Reyna as his stock continues to soar and Raphael Wicky, who worked with the youngster in the U.S. Under-17 ranks, believes a big-money transfer could be on the cards at some stage.

Wicky, who spent time in Germany during his playing days and is now coach of MLS side Chicago Fire, told Sport Bild : "Gio Reyna has star potential.