Yeah I know what most will be thinking if you just read this title and don't know about Hernandez will be thinking. "So what? Lots of people are promoted to AA". Very true, but let me just shead light on who this kid is (cause he is just a kid) if you don't know already.
Felix was born 4-8-1986. So yes that means he just turned 18 this year. Last year as a 17 year old he dominated the M's short season and Low A ball in the minors. So this year the M's decided to challenge him in High A at the age of 18. Just so some people understand if they don't follow prospects too much. If this kid was born in the U.S. he would be pitching as a senior H.S. Not in High A were even the very youngest players are still 19-20.
So make it somewhat simplified, he just flat out dominated High A competition that he was very very young for and that was much older then himself. His stats go as 2.73 era and a whip of 1.21. He pitched 92 innings and k'd 114. Not to mention that the league he was pitching in, the California league, is considered to be a hitters league.
Now he has been promoted to Double A, less than 3 months after turning 18. He was already very young for his age and now being promoted this early there isn't much more you can say except it's very rare.
Instead of giving my own scouting report on him, I'll quote the one from ESPN Down on the Farm by John Sickels.
Hernandez has a lanky build and is still growing into his body. It is conceivable that he could pick up additional velocity. Since he already hits 94-97 mph, adding additional strength to his frame could push his fastball into the 97-100 mph range. Even if that doesn't happen, his fastball is plenty fast. Hernandez doesn't have just heat: he also has a nasty curveball that is much more refined than typical for pitchers his age. His changeup is somewhat erratic, but still very good at times. Hernandez's command and control also rate as above-average for his age group. He mixes his breaking ball, changeup, and fastball with aplomb, and his ability to throw strikes most of the time makes him very special. He also has good pitching instincts, and better emotional maturity than the vast majority of 21-year-olds, let alone 18-year-olds. Hernandez is a good athlete, but he needs additional experience with things like fielding his position and holding runners. That will come in time. Physically, emotionally, and intellectually, he has everything you look for in a pitching prospect."
Oh yeah and if your in keeper leagues w/ prospects, I would say get him quick, really quick. Cause he will be a very well known prospect name soon.