The New York Knicks' new $100 million man, power forward Amar'e Stoudemire, can be an unstoppable force on the court, but a lack of insurance on his contract will keep him from competing in next month's FIBA World Championships.

The Knicks broke the news to Mr. Stoudemire just days after he Tweeted: “There isn't anything that would stop me from playing for the U.S.”

But apparently lack of insurance on his fragile 6-foot-10-inch, 249-pound frame will.

Insured players, according to reports, don't need permission to compete for national teams, but Mr. Stoudemire's $100 million contract is not covered due to his injury history.

Mr. Stoudemire, who came to the Knicks organization this summer from the Phoenix Suns via free agency, has suffered several injuries during his career. In 2005, he had microscopic knee surgery, followed by a detached retina in 2009—two of the major blemishes on the 27-year-old's health report card.

“He really wanted to play but understood our position,” Donnie Walsh, president of the Knicks, told reporters. “He was a man about it.”

Mr. Stoudemire played for the United States in the 2007 Olympic qualifying tournament.