Brian Windhorst of ESPN reported the update Saturday.
Randle, who signed with the Knicks as a free agent in July after spending last season with the New Orleans Pelicans, joins a long, star-studded list of American players who either opted out of international duty this summer or took their name out of consideration after being named to the preliminary roster.
The 24-year-old Dallas native averaged a career-best 21.4 points along with 8.7 rebounds and 3.1 assists while shooting 52.4 percent from the field across 73 appearances last season.
"I improved every year," Randle told reporters after signing with the Knicks. "I take a jump and I improve. This is going to be my biggest jump. I understand [the disappointment in NYC]. That fanbase is starving for [us] to be competitive every night to win. I'm going to work my butt off to get to that point, absolutely."
His exit from Team USA leaves the Houston Rockets' P.J. Tucker as the only traditional power forward on the roster. It could force the Americans to utilize more small-ball lineups with a stretch 4.
Training camp kicks off Monday in Las Vegas and runs through Aug. 30 with stops in Australia. The team's first World Cup game comes Sept. 1 against the Czech Republic in China.
It's unclear whether Randle will be replaced on the roster.