Drafted by the Oakland Athletics in 1980, Tettleton spent four years in the minor leagues before making his major-league debut in 1984. Tettleton fell victim to several unusual injuries with Oakland, missing almost half of 1985 with a pinched nerve in his back and part of 1986 with an infected foot. The Athletics tired of his inability to stay healthy and released him on March 27, 1988.
Signed by the Baltimore Orioles on April 5, 1988, Tettleton began to produce. He platooned at catcher with Terry Kennedy that year and hit eleven home runs in just 283 at-bats. In 1989, his career took off, as he hit 26 home runs and was named to his first All-Star team. His wife attributed his dramatic improvements to his consumption of Froot Loops cereal, and he was nicknamed “Froot Loops” soon after.
Tettleton was traded to the Detroit Tigers for Jeff Robinson on January 12, 1991. He became a fan favorite for his power displays, twice clearing the right-field roof at Tiger Stadium with mammoth home runs off Kirk McCaskill and Jaime Navarro. With the Tigers, Tettleton began catching less to relieve pressure on his knees, splitting time between the backstop, first base, and designated hitter positions.
Tettleton signed with the Texas Rangers as a free agent on April 12, 1995 to serve as the Rangers’ full-time designated hitter. He turned in two solid seasons in Texas, hitting 58 home runs and walking 212 times from ’95 to ’96. A knee injury ended his career early in the 1997 season.
An odd batting stance in which Tettleton held the bat straight up next to his head led to lots of strikeouts, as he was forced to commit early and had trouble laying off change-ups and breaking balls. However, he also possessed a wonderful batting eye. The only player in baseball to walk at least ninety times a year from 1990 to ’96, Tettleton led the league with 122 free passes for the Tigers in 1992.