Guerra showed in his 2006 debut that he had the pitches and the command to succeed. He didn't begin to dominate until this season, when he added the five miles an hour to his fastball--up to 95 mph--that his 6-foot-5 frame suggested he would. Yet the most impressive thing about Guerra might be that he turned 18 just this season

It's not easy being the youngest player in the Double-A Eastern League, as Martinez has proved with so-so play this season. But consider that at age 18, he's younger than most 2007 high school draft picks. Martinez' calling card is his bat, and he profiles to have the power and arm for right field.
He's gonna be the best prospect in all of baseball next year.
