From BR Bullpen
- Bats Right, Throws Right
- Height 6' 3", Weight 210 lb.
- High School Belen Jesuit High School
 Biographical information
Gaby Hernandez has been a minor league starting pitcher from 2004 to 2011. He was drafted in the third round of the 2004 amateur draft by the New York Mets. He was signed by scout Joe Salermo. His uncle Vicente Diaz played in the minors.
Hernandez began his professional career in 2004, splitting the season between the GCL Mets and Brooklyn Cyclones. In 10 games with the GCL Mets, he went 3-3 with a 1.09 ERA and 58 strikeouts in 49 2/3 innings. He allowed only 25 hits for a .150 opponent average. He appeared in only one game for the Cyclones, going 1-0 with six strikeouts in three innings of work. He tied Jair Jurrjens for the Gulf Coast League lead in complete games (2), was 5th in strikeouts (5 behind leader Gabriel Sosa) and easily led in ERA, .66 ahead of runner-up Scott Mitchinson. Despite his success, Mitchinson beat him out for the All-Star SP honors. Baseball America ranked him as the #2 prospect in the circuit, between Luis Soto and Greg Golson.
In 2005, he played for the Hagerstown Suns and St. Lucie Mets, going 6-1 with a 2.43 ERA and 99 strikeouts in 92 2/3 innings with the Suns (18 games started). On June 19, he threw a no-hitter against the West Virginia Power. He slumped with St. Lucie, however, going only 2-5 with a 5.74 ERA in 10 games started. Overall, he went 8-6 with a 3.47 ERA in 28 games started. In 135 innings, he struck out 131 batters and allowed 107 hits. Baseball America named him the #18 prospect in the South Atlantic League right ahead of Ian Desmond. On December 5, 2005, he was traded with fellow minor leaguer Dante Brinkley to the Florida Marlins for catcher Paul Lo Duca.
He spent the 2006 season with the Jupiter Hammerheads, going 9-6 with a 3.68 ERA in 20 games (19 starts) before missing the final month with a sprained right toe. He was 8th in the Florida State League in ERA. Baseball America rated him as the #13 prospect in the league, just ahead of fellow hurelrs Johnny Cueto, Jaime Garcia and Jair Jurrjens. Hernandez spent the winter in the Puerto Rican League, going 3-2 with a 4.14 ERA.
With the Carolina Mudcats in 2007, he went 9-11 with a 4.22 ERA in 28 games started. He made the mid-season Southern League All-Star Game. Baseball America tabbed him as the 19th-best prospect in the league, just ahead of Alcides Escobar.
In 2005 and 2006, he was ranked the third-best prospect in the Mets organization by Baseball America. He was ranked the third-best prospect in the Marlins organization in 2007 and the fifth-best prospect in their organization in 2008.
He began the 2008 season in the Marlins organization, going 2-8 with a 7.24 ERA in 13 games started with the Albuquerque Isotopes and missed a month with an injury. He also started four games with the Mudcats; he went 3-0 with a 4.30 ERA. On July 31, 2008 - the trading deadline - he was traded to the Seattle Mariners for pitcher Arthur Rhodes. He went 1-1 with a 5.01 ERA in six games started with the West Tenn Diamond Jaxx, the team he played with following his trade. Overall, he went 6-9 with a 6.13 ERA. He went 2-5 with a 7.67 ERA for the Peoria Javelinas in the Arizona Fall League.
Sources include the 2005-2008 Baseball Almanacs and 2009 Mariners Media Guide