The roster for this tournament is very different from the 2012 London Olympic roster. There are just four players who played in the London Olympics.
Here is the roster (Olympic players are bolded):
Chay Lapin, Goalkeeper (Long Beach, CA/UCLA/NYAC)
Andy Stevens, Goalkeeper (Villa Park, CA/LMU/NYAC)
Ryan Bailey, Center (Long Beach, CA/UC-Irvine/Newport WPF)
Tommy Corcoran, Center (Coronado, CA/USC/Olympic Club)
Jesse Smith, Defender (Coronado, CA/Pepperdine/NYAC)
Jeff Powers, Utility (San Luis Obispo, CA/UC-Irvine/Newport WPF)
Alex Bowen, Attacker (Santee, CA/Stanford/Stanford)
Griffin Lerman, Defender (Monte Sereno, CA/UC-Irvine/Newport WPF)
Jeffrey Schwimer, Center (Beverly Hills, CA/Stanford/NYAC)
Nikola Vavic, Attacker (Rancho Palos Verdes, CA/USC/Trojan WP)
Bret Bonanni, Attacker (Huntington Beach, CA/Stanford/Stanford)
JP MacDonell, Attacker (Redwood City, CA/Pepperdine/Olympic Club)
Scott Davidson, Attacker (Seal Beach, CA/UCLA/NYAC)
This list of players are one's that are up and coming college stars and others who have played at the club level overseas. This tournament is a big deal since if the United States finishes in the top two they earn a spot for the FINA World Championships in July.
In saying that, the competition is not that stiff in Argentina, Brazil and host Canada. None of those teams qualified for the Olympics, but the United States should have no trouble advancing even with a mix of new players and interim national team coach in Jovan Vavic.