Karros was drafted by the Los Angeles Dodgers in the 6th round of the 1988 Major League Baseball Draft. He made his Major League debut as a pinch runner on September 1, 1991 against the Chicago Cubs. He made his first start, at first base, on September 4, 1991 against the St. Louis Cardinals, when he was 0 for 3 with 2 strikeouts. Karros recorded his first Major League hit as a pinch hitter in the bottom of the 12th inning against the Cincinnati Reds Milt Hill on September 16, 1991. The hit was a 2 RBI double to left field. In 14 appearances during the 1991 season, he only had the 1 hit in 14 at-bats.