JACKSONVILLE ? LeBron James may be the youngest player on the U.S. Olympic basketball team, but you can hardly tell by looking at him or by watching him play.

The first thing that hit me about him is the guy is huge," says assistant Olympic coach Gregg Popovich of the San Antonio Spurs. "I was shocked. He's thick and he's tall. He's just so much bigger than I thought he was."

Listed in the USA Basketball media guide at 6-8, 240, James looks about 2 inches taller and 10 pounds heavier and has a nearly perfect basketball build.

After only two days of practice in preparation for next month's Olympics, James has been just as impressive with his knowledge of the game and understanding of what the coaches are trying to teach as he has been with his physical skills. James, who will be 19 years and seven months old when the Games open Aug. 13, is the youngest U.S. male basketball player to participate since Spencer Haywood in 1968 (19 years, five months).

"He really understands the game," Popovich adds. "Some guys get it and some guys don't. This guy knows what's going on ? spatial relationships on the court, where the ball should go, what's going on, what position to be in on the court to make a steal. He really understands how to play the game."

James is so good, in fact, that he doesn't even have a position.

"I just want him to play," says head coach Larry Brown. "He already knows how to run every position."