George leaped to contest a fast-break layup by James Harden with 9:33 left in the fourth quarter and his leg smashed against the bottom of the backboard stanchion.
Trainers immediately ran onto the floor and after roughly 10 minutes of stoppage, George was taken out of the arena on a stretcher. With players looking visibly upset, coach Mike Krzyzewski then announced to the crowd that the scrimmage would not be finished out of respect to George and his family.
“There’s no way the game could have gone on under the circumstances,” USA Basketball chairman Jerry Colangelo said.
The White team led George’s Blue team 81-71.
George was considered a lock to make the final 12-man roster for the World Cup of Basketball that starts later this month in Spain.
The Americans planned to reduce the 20-play pool to 14 or 15 players today, but put off those plans after George’s injury.
“Everything’s on hold right now and it should be,” Krzyzewski said. “It would be so inappropriate for us to talk about anything else when there’s a serious injury like this.”
The defending champion U.S. team had already been weakened by player losses. Forwards Kevin Love, Blake Griffin, LaMarcus Aldridge and NBA Finals MVP Kawhi Leonard had all pulled out in recent weeks.
George would have been a candidate to start for the Americans alongside Kevin Durant. Krzyzewski and Colangelo refused to discuss the roster after the game, saying they didn’t even know when they would make roster reductions.
The Americans have to be down to 12 players before they open the tournament on Aug. 30.
The U.S. is scheduled to take the next week off before reconvening in Chicago for its next practice on Aug. 14.