The announcement was made on Fox Sports 1 during halftime of the international friendly between the USA and Venezuela. An official release with further detail was sent out by US Soccer moments later.
Dax McCarty, of course, is already with the USMNT for the Venezuela friendly tonight and for World Cup Qualifiers over the next week. The USA will host Trinidad and Tobago in Colorado on Thursday before traveling to face Mexico at the Estadio Azteca next Sunday.
Matt Polster has yet to earn an official cap for the USMNT. He has experience with the U23s and was called up to the senior squad (but unused) for off-window international friendlies against Iceland and Canada in January 2016.
While this is just the provisional roster, it does present a golden opportunity to prove their respective cases for inclusion in a major international tournament this year. And with the 2018 World Cup looming on the horizon, this is an opportunity that neither player can afford to pass up.
Per tournament rules, USMNT head coach Bruce Arena must choose and submit his final 23-man roster for the Gold Cup no later than June 27th. Training camp for the Gold Cup begins on June 25th and the first group stage game for the USMNT is on July 8th against Panama.
The full 40-man provisional roster is below.
DEF: Matt Besler (Sporting Kansas City), Steve Birnbaum (D.C. United), Greg Garza (Atlanta United FC), Omar Gonzalez (Pachuca), Matt Hedges (FC Dallas), Eric Lichaj (Nottingham Forest), Matt Miazga (Chelsea), Justin Morrow (Toronto FC), Matt Polster (Chicago Fire), Jonathan Spector (Orlando City SC), Jorge Villafaña (Santos Laguna), Graham Zusi (Sporting Kansas City)
MID: Paul Arriola (Club Tijuana), Alejandro Bedoya (Philadelphia Union), Michael Bradley (Toronto FC), Joe Corona (Club Tijuana), Dax McCarty (Chicago Fire), Tommy McNamara (New York City FC), Darlington Nagbe (Portland Timbers), Kellyn Acosta (FC Dallas), Chris Pontius (Philadelphia Union), Christian Pulisic (Borussia Dortmund), Cristian Roldan (Seattle Sounders FC), Kelyn Rowe (New England Revolution), Kenny Saief (Gent), Wil Trapp (Columbus Crew SC), Gyasi Zardes (LA Galaxy)
FWD: Juan Agudelo (New England Revolution), Jozy Altidore (Toronto FC), Clint Dempsey (Seattle Sounders FC), Dom Dwyer (Sporting Kansas City), Jordan Morris (Seattle Sounders FC), C.J. Sapong (Philadelphia Union), Chris Wondolowski (San Jose Earthquakes)