USA Basketball will now be able to wait until after the conclusion of the NBA Finals to submit a final roster for the London Olympics to the US Olympic Committee.
USA Basketball chairman Jerry Colangelo says the original deadline of June 18 had been pushed back three weeks to July 8, three days into a six-day US team training camp in Las Vegas.
Final 12-man rosters are not due to Olympic officials until July 27.
The Americans have added NBA Sixth Man of the Year James Harden of Oklahoma City and Anthony Davis of US college champion Kentucky to the lineup of prospective Olympians in the wake of several injuries during the NBA season.
Center Dwight Howard and playmaker Derrick Rose, both part of the original 20-man US finalist lineup, have been sidelined with injuries that will keep them from playing in London.
USA Basketball has not decided how many players will be invited to the training camp in Las Vegas.
The Americans have won 13 Olympic gold medals, including four of the past five since NBA talent was allowed to compete in the Games. The US team settled for third in 2004. With NBA players, the Americans have a 37-3 Olympic record.
Among the healthy NBA players who are finalists for the American roster are NBA scoring champion Kevin Durant, five-time NBA champion Kobe Bryant, Miami Heat playmakers LeBron James and Dwyane Wade and New York's Carmelo Anthony.