The left-handed Marlins reliever, and the organization's No. 20 prospect, was recalled from Triple-A New Orleans on May 25 and caught the earliest flight to Miami he could get from Reno, Nev. He arrived at Marlins Park about a half-hour before first pitch and hastily threw on his uniform and warmed up.
A few hours later, Jennings wound up with his first career win thanks to a sixth-inning relief appearance.
Soon enough, Jennings won't be the only top Marlins youngster playing in the big leagues, as five of the organization's top 10 prospects are projected to make their Major League debuts within the next year.
Leading the way is Christian Yelich, the team's top prospect and top Draft pick two years ago. Yelich, who was taken 23rd overall in the 2010 First-Year Player Draft, is just 20 years old, but finished last season in the top 10 in many offensive categories in the South Atlantic League, including finishing third in the batting race. This season, Yelich has hit .276 with seven home runs in 42 games for the Jupiter Hammerheads.
Yelich is a solid outfielder with power and the threat to steal bases -- he has 11 so far this year -- and he appeared to be on the fast track to the big leagues before being sidelined earlier this month with a concussion. Still, the 6-foot-4, 189-pounder is expected to reach the Majors by 2013.
While Yelich is the Marlins' top overall prospect, Matt Dominguez, ranked No. 2, could arrive sooner. Dominguez had a chance to be the team's third baseman a year ago, but he struggled in Spring Training and was sent down. Some uncertainty surrounds his future with Hanley Ramirez's move to the hot corner, but Dominguez is a Gold Glove-caliber third baseman and ranks eighth among all prospects at third.
The Marlins also have a trio of highly touted arms among their top Minor Leaguers, spearheaded by 2011 first-round pick Jose Fernandez, the organization's No. 3 prospect. Fernandez has been dominant for Class A Greensboro, sporting a 1.50 ERA in 11 starts entering Wednesday. He has 78 strikeouts compared to 15 walks and has a 0.90 WHIP while holding opponents to a .190 batting average. The 19-year-old's callup is still a while away, with the team expecting him to be big-league ready in 2015.
Fellow 2011 selection Adam Conley is 6-2 with a 2.56 ERA and a 1.01 WHIP for Greensboro. The Marlins project the lefty as a starter, but he could be a reliever as a fallback plan and is expected to reach the Majors next season.
Rounding out the trio of pitchers is 2009 first-round selection Chad James, a left-handed hurler out of Oklahoma -- much like current Marlins pitcher Josh Johnson and 2012 first-round pick Andrew Heaney. James has struggled with command in the Minors, but still has the potential and the stuff to be a top-of-the-rotation pitcher when he reaches the Majors, which could be as early as next year.
Tom Green is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.