Billy Hamilton, Reds
Billy Hamilton, 23, has just 19 major league at-bats to his name and is on this list for precisely one reason: He's fast. Hamilton combined to steal over 250 bases from 2011-2012 while working his way up from Dayton to Bakersfield to Pensacola. After spending the first part of last season in the minors, he was promoted late last fall to Cincinnati, where he nabbed 13 bases in 13 games. By all accounts, the Reds are giving him a shot to be their starting center fielder out of spring training, but it's no gimme. He'll have to earn his ticket from Arizona to Ohio by showing strong defense, a good eye at the plate, and a knack for putting the ball in play.