The sixth in a series by SportsDay's Gerry Fraley on the top prospects at each position in the Texas Rangers' minor-league system. Players on the major-league roster are not included.OUTFIELDMIGUEL APARICIOAGE: 18HOW ACQUIRED: Signed as an international free agent out of Venezuela. Received $500,000 signing bonus.NEXT STOP: Aparicio opened last season at the Low-A South Atlantic League before dropping down to the Short-season A Northwest League.