William Francis Plummer(born March 21, 1947 in Oakland, California) was a catcher for the Chicago Cubs, Cincinnati Reds, and the Seattle Mariners. While never a regular player (he was Johnny Bench’s backup catcher during the Big Red Machine years), he did play solid defense. He was a lifetime .188 hitter (he only batted above .200 three times in his career). After he retired, he stayed in the Mariners system. He managed the Wausau Timbers in 1981. He was the Mariners’ third base coach, and when Jim Lefebvre was fired after the 1991 season, he was hired as manager. The Mariners finished in last place in his only season in Seattle, going 64-98. Prior to a game on April 16, 1992 against the Chicago White Sox, Plummer presented to the umpires a lineup card that listed two first basemen and no designated hitter; when the error was discovered, the team was forced to insert its pitchers into the batting lineup, instead of using a designated hitter, for the remainder of the game. The Mariners went on to lose the game 5-4. Plummer has managed in both independent and minor league baseball having managed the Western Baseball League’s Chico Heat from 1997–2000 and was recently hired to manage the Arizona Diamondbacks’ Triple-A affiliate, the Tucson Sidewinders. He is currently the catching instructor for the Diamondbacks.