Rafael Pineda is a senior right-handed pitcher for the Texas AM Aggies. He was selected by the Cincinnati Reds in the 40th (last round) round of the draft in 2012 but decided to come back to A&M. I got to see one of his outings against Arkansas on ESPN, which has a broadcast gun, so I charted his pitches.
Out of the 62 pitches I charted (I missed at least two or three because the velocity wasn't shown on the screen, but it was also a short outing), I counted 4 different pitches Pineda threw:
4-seam fastball: 6 (9.7 %) thrown at an average MPH of 89.5, maxing out at 91 MPH.
Sinker: 26 (41.9 %) thrown at an average MPH of 89.42, maxing out at 91 MPH.
Slider: 28 (45.2 %) thrown at an average MPH of 80.86, maxing out at 84 MPH.
Changeup: 2 (3.2 %) thrown at an average MPH of 79, maxing out at 79 MPH.
Looking at MLB comparisons in the Pitch F/X era, you are obviously going to have to start with sinker/slider guys. You don't see any qualified pitcher in the Pitch F/X era throwing that many sliders, which I feel like I have said before when talking about a college pitcher. As far as sinker velocity goes, Slowey, Looper, Lohse, and Cahill are the closest comparisons. Slowey is the best comparison as far as fastball velocity out of the group, as his 4-seamer doesn't gain hardly any velocity from his sinker. Of course, all 4 pitchers have harder sliders and changes, and have all shown curveballs off in the majors, something Pineda didn't do in the outing I saw him in.
Obviously the velocity is just mediocre, so he isn't a big prospect. The high volume of sliders is concerning, and the sinker/slider skillset is not one that works very often in MLB rotations. It just isn't MLB stuff, and he doesn't have Kevin Slowey's command.
I also saw Colby Suggs of Arkansas pitch out of relief and throw in the 9th inning. He threw just 13 pitches, but it seemed enough to get a look at his two pitches.
He threw 7 fastballs that averaged 95.57 MPH. Out of the 299 qualified MLB relievers in the Pitch F/X era, only 21 have better fastball velocity than that.
The other 6 pitches were sliders that averaged 84.67 MPH. That fastball and slider velocity meshes very well with John Axford's. Axford has obviously had some problems over the last couple of years, and he had a long and weird road to the big leagues, but he had two really dominant years in 2010 and 2011.
Suggs isn't quite a J.T. Chargios or Damien Magnifico as far as fastball velocity coming out of the 2012 draft, but it is really elite velocity and clearly MLB stuff. The slider has to get some more command, but if you don't mind taking a reliever early, then I don't think you worry too much about it at this stage.