The White Sox have signed 16-year-old Colombian catcher Jhoandro Alfaro for $750,000. The younger brother of Rangers catching prospect Jorge Alfaro, Jhoandro also has a strong arm and is a more advanced defensive catcher than his older brother was when he signed, though he doesn’t have Jorge’s raw power or speed. Alfaro, who has been training in the Dominican Republic with Rafael Montero (known as “Spilman”), has grown taller since the beginning of the year and worked hard to transform his conditioning, now checking in around 6-foot-1, 180 pounds. Some scouts felt his righthanded bat will need time to catch up to his defense. Alfaro played in the Dominican Prospect League.