Recently, Joe Frisaro of MLB.com discussed the Miami Marlins' pitching prospect depth, which has been sapped in recent years by trades. The Marlins dealt Andrew Heaney and Anthony DeSclafani, two guys with good minor league track records and, at least in Heaney's case, strong pedigree, in order to help acquire Dee Gordon and Mat Latos. One year later, both starters posted decent seasons for their respective teams while Miami is spending time searching for a starting pitcher.
The reason for that is that, contrary to Frisaro's article, the Marlins' pitching prospect depth is not good and is not ready for the majors. In fact, most of those starters may not even be headed for starting in the majors, and the likely path for many of them appears to be the bullpen. Looking at the preliminary top 35 Marlins prospects over at Minor League Ball, John Sickels lists 20 pitchers. Of those pitchers, only five of them essentially spent the majority of their careers as relievers. The remaining 15 have mostly spent their time as starters, but a glance at those names will show that their futures may all end up being in relief sooner rather than later.
Austin Brice
Brice always had a risk of being thrown into relief, and after failing to control his pitches and continuing a three-pitch mediocre arsenal beyond his fastball, that time may be coming as early as 2016. Brice was always a promising player, having ranked highly in most Marlins preseason prospects lists, but now heading into an age 24 season and likely repeating Double-A, he may finally get his first regular reps out of the rotation. Luckily for the Marlins, his stuff will play up well in that department, and pitching one inning may help the control situation.
Jeff Brigham
Brigham was acquired in the Mat Latos - Michael Morse trade with the Los Angeles Dodgers and he remains the best name the Fish acquired in that deal. He has hard stuff from the right side, with a fastball topping at 97 mph, and a strong slider as well. However, he has struggled with control, and he has already suffered one UCL injury requiring Tommy John surgery back in college in the University of Washington. Without a solid changeup, he is an ideal eventual candidate for transition to the pen.
Kendry Flores
Flores has worked in the pen for the Fish, but he will get a chance to start again in Triple-A, where he fared well last season. The problem is whether or not Miami can depend on his stuff, primarily based on deception rather than swing-and-miss potential, will play up in the majors. His strikeout rate dipped last year in Double- and Triple-A despite the good numbers, and there is a concern of a similar drop like Jose Urena suffered last year. Unlike Urena, however, Flores lacks good velocity that would look significantly better in the pen, so it may be starter or bust for him.
Jarlin Garcia
Garcia has a similar situation to Flores, but he is at least a level behind at age 24. Garcia's advantage is as a lefty, where his kind would always be needed to fill a potential LOOGY role. He has a reasonable fastball for a left hander but average or fringe average secondary options that may betray his chances of starting.
Tyler Kolek
This would be the most concerning situation. Kolek was drafted second overall in the 2014 draft in order to be a top starting pitching prospect with high-end velocity and durability. However, Kolek's first professional year saw him struggle against older competition in Low-A Greensboro, but also saw him flail around with his control while throwing low-to-mid 90's fastballs instead of high-90's heat. He is still young, but if he continues to stall in development, a switch may be warranted.
Matt Milroy
Milroy had one strong half-season in Low-A Greensboro after being drafted out of IUC in 2012 in the 11th round. The righty showed promise at the time with a low-to-mid 90's fastball and strong slider with good movement away from righties. However, he has minimal control, and he struggled with that even after a permanent pen move this season in High-A Jupiter. He struggled with a starting role last year in Jupiter and the Marlins pulled the trigger on a pen move. He did better, with a 3.25 ERA and 3.53 FIP, but also walked 15.3 percent of batters along with a necessary 28 percent strikeout rate.
Ivan Pineyro
Pineyro is a low-ceiling prospect acquired by the Marlins in the Dan Haren deal. He was pitching well in Double-A and continued that trend with a 2.70 ERA and 3.71 FIP in six starts in Triple-A New Orleans. However, like Kendry Flores and many other Marlins starters, he is mostly a strike-thrower who is getting by working in the zone against minor leaguers who may still make weak contact. He works low-90's on his fastball with a fringy secondary repertoire of several pitches. He likely profiles in the pen as well, where he can tone down his four-pitch group into two pitches and work primarily versus righties.
Chris Reed
Reed was acquired by the Marlins for Grant Dayton, another minor league lefty reliever. The Fish got the player with the brighter upside, as Reed is a former first-rounder from Stanford, but it does not appear that upside will pan out. Reed was started in the Dodgers organization as a starter, but he returned to primarily relief this year after his control continued to falter in longer stints. It has not really returned in relief, and Reed isn't some hard thrower who can occasionally blow it past guys. He threw 91 mph with his fastball and a good secondary slider and not much else.