He spent several years playing for local amateur teams, such as the Portland Babes, Bend Elks and Silverton Red Sox.

Another version has it that an Oregonian sports editor asked about a certain pesky hitter he'd watched play, seemingly unaware of the similarity to the player's actual surname.

In 1940, he played for the Rocky Mount Red Sox of the Piedmont League, where he was a teammate of future Hall of Famer Heinie Manush, who was the team's player-manager.

In the 1947–48 offseason, the Red Sox acquired shortstop Vern Stephens, a three-time All-Star, and asked Pesky to move to third base.

[14] Pesky began his coaching career in the New York Yankees organization with the 1955 Denver Bears of the Triple-A American Association working under manager Ralph Houk.

[16] The team's standout performer, relief pitcher Dick Radatz (converted to the bullpen by Pesky at Seattle in 1961), had saved 12 games and won seven others with a 1.16 earned run average to keep the Red Sox in contention to that point.

But the team buckled from poor defense and, apart from Radatz and 20-game-winning starter Bill Monbouquette, lack of pitching depth; it went only 36–55 for the rest of the campaign to finish 76–85 and in seventh place in the ten-team American League.

The following year, despite another strong contribution from Radatz and the debut of star 19-year-old rookie outfielder Tony Conigliaro, the 1964 Sox continued to languish in the second division, winning only 70 of the 160 games Pesky managed.

From 1965 through 1967, he served as first-base coach for Pirate manager Harry Walker, who had hit the double that scored Enos Slaughter with the winning run in the eighth inning of Game 7 of the 1946 World Series—the play on which Pesky was rather dubiously [17][18][19][20] accused of "holding the ball" on a relay from the outfield, allegedly hesitating as Slaughter made his "mad dash" for home from first base.

After Walker's firing in 1967, Pesky managed the Bucs' Triple-A farm club, the Columbus Jets of the International League, to a second-place finish in 1968.

A few days after he took on the job, his old friend Ted Williams, newly named manager of the Washington Senators, asked Pesky to be his bench coach and top aide.

As in Pittsburgh, he worked at first base and, in his first season back on the field, the Bosox won the 1975 American League East title, swept the three-time world champion Oakland Athletics in the 1975 American League Championship Series, and battled the Cincinnati Reds in a thrilling, seven-game World Series.

The Red Sox had been contenders for most of the late 1970s, but in 1980 they stumbled to fourth place in the AL East, resulting in Zimmer's dismissal with five games left in the season.

The following season, another old friend, Ralph Houk, became Boston's manager, and Pesky resumed his role as the club's batting and bench coach.

In 1990, at age 71, he also spent almost 2½ months as interim manager of Boston's top farm club, the Pawtucket Red Sox, when the team's skipper, Ed Nottle, was fired in June.

On April 3, 2007, the North Shore Spirit, a now-defunct team in the Independent Can-Am League, in Lynn, Massachusetts, invited Pesky to sit in their dugout—and serve as an honorary coach—anytime he wanted.

As John Powers wrote for the Boston Globe, "Pesky was the stand-in for all of the Towne Teamers who'd gotten to the World Series and fell short.

Bill Simmons, who was present that day, wrote for ESPN in a column that was republished in Now I Can Die In Peace that Pesky received the biggest cheer as a living "reminder of everything that had happened since 1918."

(As others had pointed out, not only had Pesky been the shortstop during Slaughter's Mad Dash, but he had been born within six months of the 1918 World Series, and his wife's given name was Ruth.)

With the help of Carl Yastrzemski, Pesky raised the 2004 World Series Championship banner up the Fenway Park center field flagpole.

On September 23, 2008, the Red Sox announced that they would retire the number 6 Pesky wore as a player to mark his 89th birthday and his long years of service to the club.

Although he reclaimed #6 and wore it from 1981 to 1984, between 1985 and its retirement the number also was assigned to players such as Bill Buckner, Rick Cerone, Damon Berryhill and Tony Peña.