"We contacted Mr. Glass and this is what the boys wanted to do, come up here and celebrate the season," said team manager Chris Roehl.
The Royals' Double-A affiliate is the Northwest Arkansas Naturals in the Texas League.
"We helped pull this together and Mr. Glass has been very generous with his time and his team. This is a good celebration," said John Aden, one of the parents.
A traveling team, the young Naturals played more than 60 games en route to the title.
"They're 13-year-olds from Northwest Arkansas and they won the state championship -- and they're big Naturals fans, obviously," Glass said. "So they get to come up and tour the facilities and see the Royals-Red Sox game.
"And they're about as excited as 13-year-old kids can get. Wouldn't it be great to be 13 again and win the state championship and have all that excitement and then get to come up here and do this?"
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.