Buffalo Bisons of the Class AAA American Association after batting .386 with 19 doubles, 10 home runs and 66 RBI in 62 games with Akron. In 20 games with Buffalo, Casey hit five home runs and 18 RBI. On September 12, Casey was promoted to the Cleveland Indians as a September call-up. He appeared in six games for the Indians, going 2-for-10 (.200) with two walks and an RBI. Casey won the Lou Boudreau Award as the Cleveland Indians' top minor-league position player, at the conclusion of the 1997 season. Baseball America named him the #20 prospect before the 1998 season. Cincinnati Reds 1998 season On March 30, 1998, Casey was traded to the Cincinnati Reds for Dave Burba. On April 3, 1998, Casey was hit in the eye with a ball thrown by teammate Damian Jackson during batting practice, resulting in a fractured orbital, and subsequent surgery. Casey's surgery took two surgeons, operating for four hours to fix his fracture. Just three weeks after the surgery, Casey began his rehab assignment with the Indianapolis Indians, and just a week after joining the Indians, he was recalled to the Reds. Casey struggled during his first season with the Reds, his average dipped to .133, and he was sent back to Indianapolis. On June 18, Casey was recalled to the Reds. 1999 season On May 19, 1999, the Reds defeated the Colorado Rockies in a 24−12 final, tied for the fourth-highest run-scoring output in MLB history. Casey hit two of the Reds' six home runs, and reached base seven times with four hits and three walks. He also scored five runs and drove in six. He was selected to the All-Star Game for the first time in 1999. Casey produced a breakout offensive season in 1999, batting .332 with 25 home runs, 99 runs batted in (RBI), 42 doubles, and 103 runs scored in 151 games. He was fourth in the National League in batting and doubles, and sixth in singles. In 1999, he won the Hutch Award. During his tenure in Cincinnati, and later in Pittsburgh and Detroit, Sean Casey was regarded as approachable and friendly, and his nickname, "the Mayor," comes from his reputation for chatting casually with every runner who makes it to first base, and from his very public charity work. It was frequently expanded to "the Mayor of Riverfront" when the Reds played at Riverfront Stadium.