Herrera, a right-handed relief pitcher and native of the Dominican Republic, will join the World roster, while Myers, a North Carolina native, will play for the U.S. side.
A 5-foot-10, 188-pounder, Herrera started the 2011 season with Wilmington (Class A Advanced) and made eight relief appearances before being promoted to Double-A Northwest Arkansas. He's a combined 4-1 with a 1.27 ERA, having allowed just five earned runs in 35 1/3 innings, with a 40-3 strikeout-to-walk ratio.
The 21-year-old signed with the Royals as a non-drafted free agent in December 2006.
"With Kelvin, we're very pleased with they way [he's] progressed this year," Sharp said. 'He's been a starter... in the past. We converted him to a reliever this year. He's done exceptionally well. He's got three well-above-average pitches and has done a great job. He's fearless on the mound and answers every challenge that we present him with."
Myers was rated by MLB.com as the Royals' third-best prospect, even after being moved from the premium position of catcher to outfield prior to this season. Despite missing time with a knee infection, the 20-year-old Myers has batted .295 with a .366 on-base percentage and .418 slugging percentage. He's hit three home runs and driven in 14 in 39 games for Northwest Arkansas this season.
The right-hander was moved to the outfield to help accelerate his development and get his bat to the Major Leagues more quickly.
"We're really happy with his progress," Sharp said. "Obviously he got set back and missed some at-bats this year due to injury, but we're really happy with his progress in the outfield. He continues to swing the bat [well] for a young player in a very advanced league."
This marks the second year in a row and third time since 2006 the Royals have sent two players to the XM All-Star Futures Game.
"We had Eric and Mike on the team last year, obviously Wil and Kelvin this year," Sharp said. "It's a great honor for them and it's a great honor for the organization."
The 13th annual Futures Game can be seen live on MLB.TV, ESPN2 and ESPN2 HD and followed live on MLB.com's Gameday on Taco Bell All-Star Sunday, July 10, at 6 p.m. ET. In addition, XM Radio will broadcast play-by-play coverage of the event live on XM 175. MLB.com will provide complete coverage before, during and after the game, and you can keep up to date by following @MLBFutures on Twitter. Fans can join the Futures Game conversation by tagging tweets with #mlbfutures.
Major League Baseball, along with the Major League Baseball Scouting Bureau, MLB.com, Baseball America, USA Baseball and the 30 Major League Baseball clubs, selected the 25-man rosters for each club. Each organization is represented, and the World Team features players from 12 countries and territories. Players from all full-season Minor Leagues were eligible to participate.