"It's not a tryout," Colangelo added. "It's taking inventory."
Twelve players will make the team for London, which will be announced July 7, after two days of practice.
Originally, the team was to be chosen June 18.
Krzyzewski said it will be important to get players "fresh" after for most of them a grueling NBA season. As many as five players could be playing in the NBA Finals until as late as June 26.
"That's going to be the key for us being as good as we can be," Krzyzewski said, "the first few weeks and how everyone handles it, while still getting ready."
Krzyzewski confirmed that London will be his last Olympics as the head coach. He coached the Americans to the gold medal at the 2008 Beijing Olympics after working with Colangelo to rebuild USA Basketball following its embarrassing results at the 2002 world championships and the 2004 Athens Olympics.
"I think this is the last time," Krzyzewski said. "I hope we can win a gold medal."
Meanwhile, Colangelo disputed the opinion of Mark Cuban, the billionaire owner of the Dallas Mavericks, who recently said it's "stupid" of the NBA to allow its best players to play in the Olympics for free.
"I can't think of anything more ridiculous and stupid than giving away the best assets from a for-profit business to somebody else to make hundreds of millions, if not billions of dollars," Cuban said. "It doesn't get any dumber than that."
But Colangelo insisted that having top stars in the Olympics has reaped many rewards for the NBA.
"What we have done with our program, I think has brought great value to the NBA as a whole," he said. "As a good partner in the NBA, every owner should recognize that that added value has added something to their own franchise.
"The players are very valuable assets, no question about that," Colangelo added. "And the NBA gains by the success that these players have on the international stage. We are a global economy. The NBA in particular, has been at the forefront of dealing in the global marketplace. So the participation and success of the players has brought great opportunities for the NBA and its marketing efforts around the globe."
After its initial training camp in Las Vegas, which finishes with an exhibition against the Dominican Republic at the Thomas & Mack Center on July 12, the team will make several stops on its way to London.
First will be Washington, D.C., followed by Manchester, England. Its final training sessions will come in Barcelona, where it will plan Spain and Argentina 20 years after the original Dream Team made history at the 1992 Barcelona Olympics.