In 1986, Morris racked up 21 wins, and had a stretch from July 9–18 in which he threw three consecutive complete game shutouts. The Tigers headed to the postseason again in 1987 behind a team-leading 18 wins from Morris, but this time Morris' postseason performance was below expectations. He lost his only start in the ALCS, surrendering six runs in eight innings to the eventual World Champion Minnesota Twins. Despite a sub-par season in 1989 when he made only 24 starts and won just 6 games, he finished the 1980s with 162 wins, the most by a major league pitcher during the decade. In 1990, his final season in Detroit, Morris lost a career-high 18 games, though he also led the Tiger staff with 15 wins and led the AL with 11 complete games.