Davis made his major league debut on 21 April 1981 at the age of 24, and became the Cubs starting catcher as a rookie. In the earlier years of his career, Davis showed promise on offense and became a fan favorite among Cubs fans. In his second full season, 1983, he set what would turn out to be career highs with 151 games played, a batting average of .271 and 24 home runs. Davis also had 84 RBI in the same season. In 1984, he set a career high with 94 RBI and earned his first All-Star selection, as the Cubs won the National League Eastern Division title, their first title of any kind since . In the only post-season appearance of his career, Davis hit .389 with 2 doubles, 2 home runs, 6 RBI and an .833 slugging percentage in the 1984 National League Championship Series as the Cubs were defeated by the San Diego Padres in a five-game series.