The 24 year old left-handed hitter spent almost whole year in AAA and was a slightly better than average hitter. He really did it with OBP skills, as his power didn't translate from AA (from 2011) to AAA. That AA power came almost exclusively against righties. Most of it also came on the road, which isn't that surprising since San Antonio's park has played as a pitcher friendly park over the last couple of years (with park factors of 98 and 92 for the two seasons).
1st base is kind of blocked right now for the San Diego Padres with Yonder Alonzo, and even though the Padres have some good exciting infielders (Alexi Amarista and Logan Forsythe come to mind, and that is even if Headley gets traded), there is always more value if you can play 2nd base rather than just first. With his size and build, it is really difficult to see him playing 2nd base. He has a big frame and fills it out nicely.
The swing seems to be pretty quick, and clearly has an uppercut. He had some bad swings on breaking balls when I watched him. His patience seems to come on fastballs, as he isn't going to swing at low fastballs or ones out of the zone. His plate discipline isn't great, mainly because of his problems with breaking pitches, but statistically he does have a good Pit/PA along with a very good K/BB and not too many swinging strikes.
His swing isn't as pretty on high pitches, which you would expect when it comes to uppercut swings. His LD/GB/FB surprised me somewhat, as he hit more ground-balls in 2012 than I figured he would have. A lot of this seems to be because he is an extreme ground-baller against left-handed pitching. His K/BB is better against lefties, but he hits for virtually no power against them. As a first baseman, this probably limits him to being a platoon player.
His bat is sort of hard to diagnose, because he doesn't look like the no bat speed mistake hitter that you see in the PCL a lot. He also didn't hit for much power in the PCL as well. The real question is whether he can keep walking against better pitchers that throw better breaking pitches, especially if he isn't hitting for power (which would most likely make pitchers attack him more). He seems reasonably easy to pitch to, as you would go fastballs high (but most likely have to keep them in the zone) and breaking balls low. There also isn't room for him on the Padres roster, as stated above. The best bet might be for a team with a need for a left-handed hitting first basemen to make a call and put together some kind of trade for him (I can't possibly see why the asking price would be high) and give him a chance. I am not sold that he has a real big league future, but he may develop into a bench player/pinch hitter.
Leonardo Heras is someone that has been highlighted thanks to his age (22) and his big numbers in the Mexican League. He also plays mainly center field but has also played in the corners and 2nd base. He is short, at 5-8 to 5-9 but he had a .230 ISO in 2012 (it is pretty apparent his power is developing as the ISO is getting better each year). League average ISO in the Mexican League was .148.
The average pitcher is 28.4 years old and the average hitter is 29.6 years old in the Mexican League, showing just how young Heras is compared to his competition. He may have sacrificed part of his game for power as he struck out more in 2012 and saw his K/BB slip somewhat. He was reportedly looked at by the orioles and evidently (I at least can't find him on a roster) he is not playing in a winter league. Here is a video I found of him hitting: