Las Vegas: Indiana Pacers star Paul George suffered a grisly lower right leg injury on Friday in a United States intra-squad scrimmage in preparation for the Basketball World Cup.

The injury was bad enough that the exhibition before fans at the Thomas and Mack Center was immediately halted and George was quickly hospitalised.

He later tweeted his thanks for the outpouring of concern he received.

“Thanks everybody for the love and support. I’ll be OK and be back better than ever!!!” he said.

Although he was upbeat, the reaction from those who saw the injury occur — either first-hand or via video replays, showed just how shocking it was.

“It was difficult to watch the injury that Paul George sustained tonight while representing his country,” NBA commissioner Adam Silver said in a statement. “The thoughts and prayers of all of us at the NBA are with Paul and his family.”

The Pacers’ small forward landed hard and his leg buckled horribly near the basket stanchion after he had fouled James Harden on a drive early in the fourth quarter of the contest.

Harden immediately doubled over in shock upon seeing the injury to his US teammate and medical personnel, US coach Mike Krzyzewski and members of George’s family attending the game moved to comfort the stricken player.

After George had been taken from the court with his leg in a splint, Krzyzewski announced that the contest would be halted.

“With the serious injury that we had and the fact that we stopped playing for a long period of time, and out of respect for Paul and his family, the scrimmage is done,” he told the crowd.

USA Basketball chairman Jerry Colangelo did not immediately confirm the exact nature of the injury, but said the organisation’s only concern at the moment was for the player.

“This is a very tough blow,” a grim-faced Colangelo said at a news conference. “It’s a tough situation for our entire organisation, our coaches and players are very, very emotional.”

Colangelo said decisions about the final US selection for the Basketball World Cup, to be held in Spain August 30-September 14, would take a back seat to making sure George was cared for properly.

“Our first concern, our primary concern, is Paul George,” he said. “And so, as an organisation, we’re just going to let a little bit of time go by here before we address rosters or any of that stuff. It seems unimportant.”

George, 24, has been an All-Star each of the last two years. He averaged 21.7 points, 6.8 rebounds and 3.5 assists in 80 games last season for the Pacers, who lost to Miami in the Eastern Conference finals.

Pacers president of basketball operations Larry Bird said the team was monitoring the situation.

“We are aware of the injury sustained by Paul George in Friday Night’s Team USA game in Las Vegas and we are obviously greatly concerned,” Bird said in a statement.

“At this time our thoughts and prayers are with Paul. We are still gathering details and will have an updated statement Saturday.”

None of the players on the court with George spoke to the media.

However, Houston Rockets guard Harden was among George’s NBA colleagues to use Twitter to wish the injured player well.

“Prayers go out to Paul George and his family!” Harden tweeted. “Keep ya head up G!”