In addition, Northwest Arkansas manager Brian Poldberg was named a coach for the U.S. squad which will oppose the World team. Poldberg, in his third season, directed the Naturals to a 41-28 record and the first-half title.
Moustakas, 21, has a .355 average, 17 home runs and 63 RBIs for Northwest Arkansas and leads the Double-A Texas League in each of the Triple Crown categories.
Hosmer, 20, leads the Advanced Class A Carolina League with a .356 average and 24 doubles and ranks second in on-base percentage at .425.
"They're exceeding expectations. You don't expect guys to do as well. They're both having very good years," said Scott Sharp, the Royals' director of Minor League operations. "There was a lot of pressure on them just by their draft status -- not put on by the organization but just inherent -- and it's good to see them respond and do well."
Both were first-round selections in the First-Year Player Draft -- Moustakas was picked second overall in 2007 and Hosmer was taken third overall in 2008. Each is a left-handed batter.
Moustakas is dominating the Texas League despite missing the first 15 games with an oblique injury.
"He has 17 [home runs] and he's done exceptionally well in that regard," Sharp said. "He was a high school player going out ... this would be his junior year in college and he's already in Double-A and the Futures Game."
Hosmer has just three homers but his 24 doubles and six triples have contributed to 42 RBIs.
"He's swinging the bat as well as anyone," Sharp said. "He's young and power develops late and I really don't have any concerns about him. I think you'll see, as he gets to Double-A and Triple-A, his power numbers go up."
In the field, both rate high with Sharp.
"Both he and Mike are very good defenders. I think that's overlooked just because of their bats, but both of them are very good," Sharp said.
This is the first time the Royals have had two players in the Futures Game since 2006 when Billy Butler and Alex Gordon were selected.
"That's what you're hoping for. Guys like that to do well and they have and they're recognized for that," Sharp said. "They've definitely earned it."