Ray Allen believes expansion to Europe by the NBA is a good idea.

"The league is making so much money, you've got to think how it's going to grow to the next level," Allen said Monday as the Celtics held the second day of training camp in Italy.

"People all over the world are now watching basketball," said the seven-time All-Star, who joined the Celtics in a draft-night trade. "People in the United States don't realize that there are cities over here with 4-5 million people. Those market shares would be great."