David Reyes is a 21 year old (turns 22 in April) Mexican League right-handed pitcher. I watched him pitch for Mexico in the Caribbean Series. Reyes came in to face Miguel Tejada as a right-handed reliever, and got him to fly-out to center. He would then pitch the 6th inning and would get all fly-balls (though one was an infield fly-ball).
Reyes is listed at 190 and 6-0, but looks skinny, and probably has some projection, so just size-wise, he is probably going to remain a reliever long term.
He's got impressive tilt on slider, with lots of horizontal movement to the glove side, especially late. It is a little soft at 79-81 MPH, but it darts out of the zone pretty well. I could see it being homer prone if left up.
Reyes has a 89-91 MPH fastball, that is pretty straight, but he gets a little bit of glove side movement. He seems to be a very slider/fastball heavy pitcher (but he is clearly not sinker/slider pitcher, as the fastball is thrown up high and works like a 4-seamer). He seemed to miss off the plate on the glove side quite a bit. He also broke out a slow curve at 72 MPH that breaks just up and down like a traditional 12-6 curve.
As far as his delivery goes, Reyes has sort of a high leg kick and pause, and a delivery that clearly looks like a reliever motion. The motion is not fluid, and the glove is in a weird place (away from the body and to the right) when he finishes). His arm angle is a pretty traditional 3/4 delivery.
In 2012, Reyes pitched in 30 games in the Mexican League (57 innings), mainly as a reliever. He had a 3.85 FIP, in a league where the average FIP was 4.29. Since Mexico Diablos Rojas' (Reyes team in 2012) 2 year (raw) park factor is about 113 (so just for ease, we will change average expected FIP to 4.85), this about a 79 FIP -. While his H/9IP (not a predictive statistic thanks to BABIP) was right at league average, he did a better than league average job at limiting homers. Considering he looked like a fly-ball pitcher to me, this surprised me. However, he has been a good ground-ball pitcher in Mexico, getting 45.8 GB% in his two years in the Mexican League, while league average was 43.9 % in 2012. So this is why he has been able to hold opponents to a .130 ISO and 10.4 HR/OFB % (with league average at 12.4 in 2012) in his 82.1 career innings. Of course, since he is a reliever, these numbers need to be regressed some to determine value. He does nothing especially well, that is, he is not an exceptional strikeout pitcher or control pitcher, but he has been above average, even when looking at non-homer DIPs like SIERA and kwERA as a young pitcher (only 8 pitchers 21 or younger threw at least 40 innings in the Mexican League in 2012, and only one, Remberto Romo, was better in terms of FIP).
Obviously the lack of a plus fastball makes Reyes less interesting as a possible MLB prospect (and ignoring the logistical and contract problems that sometimes arise in these situations), but he does have two breaking pitches that may not be plus, but could be MLB pitches. I would like to see more strikeouts from Reyes, but he is a little advanced for his age.