DISCLAIMER: Players eligible for this list had to have finished the 2013 season in the Minors.
5. Brent Keys
Brent Keys is, in my humble opinion, the most compelling player on this list. Drafted as an afterthought in the 17th round of the 2009 draft, Keys has quietly been reaching base at a clip slightly over .400 over the last two seasons. A lot of that has to do with his speed. Keys is pretty stoutly built but he plays the game fast and hustles on the basepaths. Keys, 23, has yet to have a season in the minors in which he has stolen less than ten bases. He might not have the kind of natural, raw speed as a player like Juancito Martinez, but Keys' definitely has enough speed to earn his spot on this list.
4. Ryan Aper
Ryan Aper is the lone 2013 draft pick (he went in the sixth round out of a community college) to make this list, but that probably has to do more with the general lack of speed in his class. Aper, 20, is built like a wide receiver, standing 6'3'' and weighing around 175 lbs. There have been rumors that Aper was clocked at a 6.5 60-yard dash, but that would put him in the Billy Hamilton range, so that's probably not very legitimate. Nonetheless, Aper does have a reputation for his speed and ability to cover a lot of ground out in the outfield, so it will be intriguing to see how much of that translates into his stats in 2014.
3. Juancito Martinez
Juancito Martinez, 24, is listed a 6'1'' but that seems like a stretch. Martinez "only" stole 27 bases in 2013, but he missed a bunch of time and very likely could have been playing hurt for a good part of the season. Overall, Martinez has almost made it to 100 career stolen bases in the lower minors. That's made even more impressive considering that Martinez hasn't posted an on-base percentage over .300 since 2009. If Martinez could find more ways to get on-base, he could easily steal more bases than any other player on this list in 2014.
2. Jesus Solorzano
Jesus Solorzano, 23, probably has the brightest future of any player on this list. His rare combination of speed and power makes him a desirable prospect. In 2013, Solorzano's first full season, he stole 33 bases and was only caught stealing four times. I haven't seen a Marlins player since Juan Pierre get out of the batter's box as fast as Solorzano. As far as pure base stealing technique goes, there is nobody in the Marlins system on the same level as Solorzano. He is close to coming in first on this list, but his stolen bases are more a result of his craftsmanship than pure speed.
Isaac Galloway is the fastest player in the Marlins farm system. He might not steal the most bases, but no other prospect is on his level in terms of pure speed. Galloway, 24, stole 31 bases in 2013 between Jupiter and Jacksonville. Drafted out of high school in the 8th round of the 2008 draft, Galloway is an extraordinarily athletic outfielder who has come a long ways since he was drafted. Galloway was almost as raw as athletic high school draft picks come back in 2008, but since then, he has shown the dedication to improve the different aspects of his game. Standing at a slim 6'3'', Galloway uses his long frame to cover a ton of ground in the outfield and hopefully his speed will translate to even more stolen bases and infield hits in the future.