Ball Boy's Quick Switch Of Derek Jeter Foul Ball Could Be Worth $10,000

— -- An enterprising New York Yankees' ball boy made a quick and possibly lucrative switch when he snagged Derek Jeter's last foul ball at Yankee Stadium, pulling another ball out of his back pocket to give to a fan and keeping the Jeter ball.

That ball could be worth as much as $10,000, a sports memorabilia expert told ABC News.

The ball boy was caught on film fielding the grounder outside the foul lines along third base in the fifth inning of Jeter's last game at Yankee Stadium. It is normal for ball boys to give away the foul balls to a lucky fan.

The Yankees' ball boy had clearly planned ahead. As soon as he cleanly fielded Jeter's shot, he reached into a back pocket and pulled out another ball, which he handed off to a fan. The ball that had been instant money -- or precious memory -- because it was hit by the retiring Yankee legend was in the kid's pocket.

According to at least one sports memorabilia expert, that move might have helped increase the price of the baseball by thousands.

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“It’s a pretty great thing, I’d love to have it for our auction,” said Kevin Bronson, director of acquisitions at Leland Sports Auction House.

Bronson said he estimated if the ball boy had handed off his catch to the crowd it would be worth between $2,000 to $4,000 today. But since sports channels have replayed the sneaky switch over and over, Bronson now estimated the foul ball to be worth approximately $10,000, although he cautioned that price will likely soon fade.

“It’s worth the most it’s ever going to be worth last night,” said Bronson. “As Jeter fades from the spotlight, so do prices."

Calls and emails to the Yankee office were not returned. The ball boy was not identified.

Bronson said each ball would have specific markings from Major League Baseball, so they can track which baseballs are authentic.

Bronson said he did not fault the ball boy for keeping that piece of Yankee history for himself.

“Every ball boy is a fan first. I’ve known an enormous amount of them over my years,” said Bronson. “He probably wanted to have a souvenir from that moment.”