Moore was undrafted out of Grand Canyon and joined the Philadelphia Phillies organization after attending an open tryout at Cherry Creek High School in Colorado.[2] He was assigned to the Bend Phillies of the Northwest League to begin his professional career in 1986.[5] In June 1988, he was promoted directly from Double-A to the National League.[2] He made his major league debut on June 14, 1988, against the Montreal Expos at Veterans Stadium.[6][7] He pitched 2+2⁄3 scoreless innings in relief of Bruce Ruffin. All three innings were ended by double plays started by Phillies second basemanJuan Samuel.[7] Moore pitched in four more games with the Phillies that season without surrendering a run. Moore spent the entire 1989 season in the minors before returning to the majors with the Phillies in 1990. He pitched in three games in relief, all in April.[6][8] It would be his final action at the major league level.[6] He was demoted to Triple-A on May 1.[9]
Prior to the 1991 season, Moore signed with the New York Mets.[10] In 1992, the Mets invited him to participate in spring training but reassigned him to the minor leagues in late March.[11][12]