Donald William Zimmer (January 17, 1931 – June 4, 2014) was an American infielder, manager, and coach in Major League Baseball (MLB). Zimmer was involved in professional baseball from 1949 until his death, a span of 65 years.Zimmer signed with the Brooklyn Dodgers as an amateur free agent in 1949. He played in the major leagues with the Dodgers (1954–59, 1963), Chicago Cubs (1960–61), New York Mets (1962), Cincinnati Reds (1962), and Washington Senators (1963–65). Shortly thereafter came a stint with the Toei Flyers of Nippon Professional Baseball in 1966.
In between, Zimmer saw action in all or parts of 18 minor league seasons spanning 1949–67. He also played winter baseball with the Elefantes de Cienfuegos and the Tigres de Marianao of the Cuban League during the 1952–53 season, as well as for the 1954–55 Puerto Rican League champion Cangrejeros de Santurce en route to the 1955 Caribbean Series. Zimmer led his team to the Series title, topping all hitters with a .400 batting average (8-for-20), three home runs and a .950 slugging percentage, while claiming Most Valuable Player honors.During a minor league game on July 7, 1953, Zimmer was struck in the head by a pitch thrown by pitcher Jim Kirk, and lost consciousness. He suffered blood clots on his brain that required two operations. He woke up two weeks later, thinking that it was the day after the game where the incident took place. This eventually led to Major League Baseball adopting batting helmets as a safety measure to be used by players when at-bat. Phil Rizzuto was the first player to use the batting helmets.Following his retirement as a player, Zimmer began his coaching career. He worked in Minor League Baseball, before coaching the Montreal Expos (1971), San Diego Padres (1972), Boston Red Sox (1974–76, 1992) New York Yankees (1983, 1986, 1996–2003), Cubs (1984–86), San Francisco Giants (1987), Colorado Rockies (1993–95), and Tampa Bay Devil Rays / Rays (2004–14). He served as manager for the Padres (1972–73), Red Sox (1976–80), Texas Rangers (1981–82), and Cubs (1988–91).