Rabelo grew up in the city of New Port Richey, Florida, and attended Ridgewood High School. Following his senior year of high school in 1998, Rabelo was drafted in the 13th round of the Major League Baseball amateur draft by the Boston Red Sox. He did not sign, however, instead choosing to play collegiate baseball for the University of Tampa Spartans. Following his junior season of college, the Detroit Tigers signed Rabelo after selecting him in the 4th round of the 2001 Major League Baseball amateur draft.