Acosta signed with the Padres for $1.8 million Friday, Jesse Sanchez of MLB.com reports.
A shortstop from the Dominican Republic, Acosta turned 16 in June, making him one of the youngest players in this class. He is also one of the best defensive prospects in the class. A plus runner with quick-twitch athleticism, Acosta is slowly growing into power and could be a big riser up prospect rankings as he matures.