A fine catcher both offensively and defensively for the Cubs from 1981 to 1987, Davis became expendable in 1988 when Damon Berryhill emerged as a capable ML player, and he was traded to the Braves on September 29 after hitting a career-low .230.

Davis was originally drafted by the Mets, but he was traded to the Cardinals organization for Ray Searage after the 1979 season. He played only 58 games in 1980 after losing 50 pounds while being treated for an ulcer, then was drafted by the Cubs following the season.

As a rookie with Chicago in 1981, Davis grabbed the starting catching job by hitting .389 in May, but lost it the following spring to Keith Moreland before regaining it during the 1982 season. In 1983 Davis hit .271 with 24 HR and 84 RBI, and in 1984 he made the NL All-Star team for the first time as the Cubs won the NL East. Davis starred in the '84 NLCS, with seven hits in five games and home runs in Games Four and Five, but the Cubs lost the final three games to the Padres after taking a 2-0 series lead.

Davis hit 21 HR and won a Gold Glove in 1986, throwing out 89 would-be basestealers, a Single Season Record with a CS% of .476, but in 1987 his durability and consistency began to lapse. He had caught at least 138 games each of the previous four seasons, and had never gone on a ML disabled list, but in 1988 an early-season stint on the DL forced the promotion of Berryhill from the minors, and Davis would catch only 76 games.