The USA is competing at the 2018 U-17 Four Nations Tournament in Mexico City, where the Shaun Tsakiris -coached squad will face the host, Argentina and Chile.Tsakiris, the U.S. U-16 boys head coach, in charge in the wake of John Hackworth having left U.S. Soccer in August for the USL's Louisville City FC, picked a 20-player roster for the Sept. 30-Oct. 8 trip during which the USA faces Argentina Oct. 4, Mexico Oct. 5 and and Chile Oct. 7. The U-17s are nine months into their two-year . . .