Yelich is on the United States squad, while Fernandez, who was born in Cuba, will pitch for the World Team.
The lefty-hitting Yelich, who attended Westlake High School in Thousand Oaks, Calif., was the 23rd overall choice in the first round of the 2010 First-Year Player Draft.
Fernandez, who turns 20 on July 31, has been simply dominating at Class A Greensboro. The hard-throwing right-hander was a first-round pick in 2011, going 14th overall.
At Greensboro, Fernandez is 7-0 with a 1.59 ERA, with an eye-opening 99 strikeouts and 18 walks in 79 innings.
The 14th annual SiriusXM All-Star Futures Game can be seen live on MLB.TV, ESPN2 and ESPN2 HD and followed live on MLB.com's Gameday on Sunday, July 8, at 5 p.m. ET. In addition, XM Radio will broadcast play-by-play coverage of the event live on MLB Network Radio XM 89. MLB.com will also provide complete coverage before, during and after the game. Fans can stay updated by following @MLBFutures on Twitter and can send/receive tweets to/from the U.S. and World team dugouts during the game by following @USDugout and @WorldDugout.
Major League Baseball, along with the MLB Scouting Bureau, MLB.com, Baseball America and the 30 ballclubs, selected the 25-man rosters.
Current Marlins who participated in the exhibition include outfielders Logan Morrison and Giancarlo Stanton, catcher John Buck, infielders Omar Infante and Hanley Ramirez, shortstop Jose Reyes and pitcher Anibal Sanchez.
"It was tons of fun getting to see new guys from different teams," said Morrison, who went 1-for-2 with two walks in the 2010 Futures Game. "Playing in a big league stadium is cool, and then I got to go to my first ever All-Star Game, so that was cool."
While the Futures Game offers young players a unique opportunity to play with and against top prospects, it also gives them a chance to have some fun.
"I remember [Angels outfielder] Mike Trout was on my team, and he was on the cover of Baseball America that month and I had him sign the cover," Morrison said. "He signs it for me and then I have him pin it up on his locker so when the media comes in, he's got his signed picture up in his locker. I don't know if he likes me anymore or not, I was just messing with him. It was a lot of fun."
As for Yelich, the speedster missed three weeks after suffering a concussion. He was hurt on May 30 and returned to Class A Jupiter on June 19.
For the Hammerheads, Yelich has posted solid numbers, including seven home runs and 19 RBIs.
He's been playing center field and batting mostly third for Jupiter in the Florida State League.
A year ago, Yelich was part of Greensboro's South Atlantic League championship team.
Fernandez has the makings of becoming a starter at the top of the rotation. Born in Cuba, he defected from his native country and went to school in Tampa, Fla., attending Alonso High School.
Twice this season, Fernandez has been named the South Atlantic League Pitcher of the Week -- for the weeks of May 29 and April 30.