The Marlins have signed 16-year-old Panamanian righthander Alberto Guerrero for $300,000. Some scouts considered Guerrero, who is 6-foot-3, 190 pounds, one of the top pitching prospects in Panama. He has touched 88 mph with two projectable pitches in his curveball and a changeup. His older brother, Jesus Guerrero, is a catcher with the Marlins’ Dominican Summer League team. Guerrero also spent time in the Dominican Republic playing in the International Prospect League and trained with German Gil.