NEW YORK, July 20 (Xinhua) -- Amare Stoudemire pulls out of the United States squad in next month's basketball world championships for Knicks's worry over his his surgically repaired left knee.

The New York Knicks forward was expected to be one of the United States' key players at the world championships in Turkey, but the team learned of the change of plans on Tuesday.

"There's too big a risk out there," Knicks president Donnie Walsh said.

New York Knicks NBA player Amare Stoudemire arrives at the 2010 ESPY Awards in Los Angeles, California July 14, 2010.

Stoudemire has had micro-fracture knee surgery among his injuries. That was one of the reasons Phoenix declined to offer him an NBA maximum length contract.

He left the Suns as a free agent and the Knicks then gave him a five-year contract worth almost 100 million dollars.

Without proper insurance, NBA teams can bar their players from taking part in summer events.

The U.S. team will be without all of the players who earned Olympic gold in Beijing in 2008.