He played in the major leagues with the Dodgers (1954–1959, 1963), Chicago Cubs (1960–1961), New York Mets (1962), Cincinnati Reds (1962), and Washington Senators (1963–1965).

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.

[4][5] During a minor league game on July 7, 1953, Zimmer was struck in the head by a pitch from Jim Kirk and lost consciousness, and developed blood clots on his brain that required two operations.

This eventually led to Major League Baseball adopting mandatory batting helmets as a safety measure to be used by players when at-bat.

Notably, he played for the 1955 World Series champion Brooklyn Dodgers, and with the 1962 New York Mets, who lost a record 120 games.

Immediately following his rookie season, Zimmer played winter ball in Puerto Rico, emerging as a dark horse 1955 Caribbean Series MVP on the heavy-hitting 1954–1955 Cangrejeros de Santurce club managed by Herman Franks.

Zimmer was beaned again in 1956 when a fastball thrown by Cincinnati Reds' pitcher Hal Jeffcoat broke his cheekbone and almost caused a detached retina[13] but he persevered.

He also caught 33 games in his final season with Washington in 1965. Zimmer served as a player-manager for the Cincinnati Reds with the Double-A Knoxville Smokies and Triple-A Buffalo Bisons in 1967.

[18] Zimmer compiled a 54–88 record for the remainder of 1972, then posted a 60–102 mark in 1973, each season finishing last in the National League West Division.

The Padres' attendance woes caused the team's founding majority owner, C. Arnholdt Smith, to sell the club amidst rumors it might move to Washington, D.C.

Working under skipper Darrell Johnson, Zimmer's tenure included a memorable event during Game 6 of the 1975 World Series.

A soft fly to left field was too shallow to score the winning run, but baserunner Denny Doyle thought Zimmer's shouts of "No!

That play, and Dwight Evans' brilliant catch off Joe Morgan in extra innings, set up Carlton Fisk's classic, game-winning home run.

[21] The Red Sox would win more than 90 games in each of Zimmer's three full seasons (1977–1979) as manager, only the second time they had pulled off this feat since World War I.

The Red Sox spent the last month of the season trading first place with the Yankees, forcing a one-game playoff on October 2.

In that game, the Yankees took the lead permanently on a home run by Bucky Dent over Fenway Park's Green Monster.

Zimmer's outright hatred of Lee ran so deep that he gave the starting assignment in the last game of the "Massacre" to rookie Bobby Sprowl, who had only been called up from Triple-A Pawtucket a few days earlier.

Reportedly, Carl Yastrzemski pleaded with Zimmer to start Lee, who, along with Luis Tiant, had dominated the Yankees during their careers.

Finally, Zimmer called on Jack Brohamer to replace Hobson on September 23; with Brohamer at third, Boston won its last eight games of the regular season to force a tie with the Yankees, but the Red Sox lost the playoff game on home runs by Dent and Reggie Jackson.

On June 6, 1995, he left the bench during the fifth inning of the game against St. Louis, which came to the surprise of players and staff (he had told Baylor about plans to retire a few weeks beforehand).

The next game, Zimmer wore an army helmet with the word "ZIM" painted on the side and the Yankees logo stenciled on the front, which was given to him by Michael Patti, a Madison Avenue advertising executive.

[28] Zimmer accepted responsibility for the altercation and was apologetic to his family and the Yankees organization but maintained that Martínez was "one of the most unprofessional players" he had ever known.

[30] (In 2014, longtime Tampa Bay third base coach Tom Foley wore Zimmer's name and number on the back of his own uniform in tribute.

From the 2008 season to his death, Zimmer was one of the last former Brooklyn Dodgers (along with pitchers Don Newcombe and Tommy Lasorda and announcer Vin Scully) still in baseball in some capacity.

At home plate before a night game in Elmira on August 16, 1951, Zimmer married Soot (Carol Jean Bauerle), whom he had started dating in 10th grade.