The left-handed hitting and throwing Abad was drafted in the 16th round (443rd overall) in the 1993 amateur draft by the Boston Red Sox, who assigned him to the Gulf Coast Red Sox of the Gulf Coast League that year. In 1994, Abad advanced to the Single-A Sarasota Red Sox, where he hit .288. He remained in Sarasota through part of 1995, advancing to the Double-A Trenton Thunder for whom he hit .240. He was sent back down to Single-A Sarasota in 1996, hit .287 for the Single-A team, and was again called up to Trenton, where he hit .277 with the Thunder.