The United States took advantage of CONCACAF's new rule for the 2013 Gold Cup, making all four allotted swaps to its roster prior to the knockout stage. Three other countries - Mexico, Honduras and Trinidad & Tobago - exchanged one player each as teams made reinforcements ahead of this weekend's quarterfinal bouts.
Jurgen Klinsmann dropped Herculez Gomez, Oguchi Onyewu, Jack McInerney and Corey Ashe and brought in center back stalwarts Omar Gonzalez and Matt Besler and attackers Alan Gordon and Eddie Johnson to replace them.
Gomez scored a goal against Guatemala in a 6-0 friendly buildup to the tournament, but in two Gold Cup appearances (one start, against Cuba) he did not score. He will join up with new team Club Tijuana ahead of the Liga MX season.
Onyewu also started against Cuba. McInerney and Ashe had not seen any minutes in the Gold Cup.
Besler and Gonzalez established themselves as the first-choice center back pairing during a five-game spell in June, and Gordon and Johnson have popped up with key goals for the Yanks in World Cup qualifying, connecting for a goal in an important semifinal round victory over Antigua & Barbuda.
Mexico, meanwhile, swapped out Monterrey defender Darvin Chavez for Morelia midfielder Jose Maria Cardenas.
Erick Norales replaces fellow defender Johnny Palacios for Honduras, and T&T called up Columbus Crew midfielder Kevan George in exchange for Khaleem Hyland.
Panama, Cuba, El Salvador and Costa Rica did not make any changes.
Follow ZAC LEE RIGG on or shoot him an email