Post sports writer Peter Botte is the author of “The Big 50: The Men and Moments That Made the New York Yankees” (available in paperback Tuesday), an entry in the popular “Big 50” sports books series. This excerpt is taken from Chapter 49: “George Costanza.”

“Ruth. Gehrig. DiMaggio. Mantle … Costanza?” When the greatest sitcom of all time (go ahead, try to fight me on this) decided to have one of its main characters take up employment at Yankee Stadium and work alongside a hilariously dead-on caricature of George Steinbrenner, well, “Holy cow,” as Phil Rizzuto would say.

The prominent inclusion of the pinstripes and several players, including Derek Jeter, Bernie Williams, and Paul O’Neill, and, especially of The Boss, in Seinfeld in the 1990s as a recurring storyline for Jerry Seinfeld’s oft-unemployed friend, George Costanza (played by Jason Alexander) was a stroke of comedic genius that even Steinbrenner and his family could not deny.

“First and foremost, we needed a job for George for the next season. He had been unemployed the year before. And we needed to give him a job,” explained Larry David, the co-creator of the show. “I was thinking, What’s a cool job for George? What job would I want to have? Well, I always wanted to work for the Yankees. So I said one day, ‘Maybe he can work for the Yankees.’ And that was it. You know, we didn’t put as much thought into these things as people think. Everything was just a whim generally.”

Of course, Jerry Seinfeld is likely the foremost celebrity New York Mets fan there is. He even featured 1986 team legend Keith Hernandez in an infamous two-episode arc in Season Three, making the retired first baseman a love interest of Julia Louis-Dreyfus’ character, Elaine Benes. So why the Yankees and not their crosstown rivals from Queens? Clearly, the easiest answer was Steinbrenner. “The chaos, the turmoil, that personality, we just thought he fit perfectly,” David said. “Frankly, the possibilities seemed endless.”

David was a longtime friend of Seinfeld’s, and the Costanza character was loosely based on him. David was born in 1947 and grew up in the Sheepshead Bay section of Brooklyn firmly in Dodgers territory. David’s older brother, Ken, however, rooted for the Yankees, a rarity in their neighborhood. That was enough for Larry. “He was four years older than I was. So naturally whatever he did, I did,” David said.

“So I became a Yankee fan, the only one of my friends on the block. And they had Mantle. You couldn’t help as a kid but idolize The Mick. The switch-hitting, all the tools, hitting it farther and being faster than everyone, he played hurt all the time, he was just a great story, a great guy to follow. I couldn’t take my eyes off him when he was up.”

David remained a die-hard fan through what he described as the “lean and horrible Horace Clarke years” in the late 1960s. When Steinbrenner purchased the team from CBS in 1973, he also remembered thinking, Who is this guy? Two more championships quickly followed on the heels of marquee acquisitions such as Catfish Hunter and Reggie Jackson, but the 1980s mostly were a constant source of frustration for fans such as David, as too many subsequent big-ticket additions didn’t result in the same success. “I never liked personally how he always signed someone else’s players, free agents, to these massive contracts,” David said of Steinbrenner. “I was such a big fan that I would follow all the kids in the farm system. I actually would look them all up in The Sporting News to see how they were doing. I kept track of these guys, but after a while none of them ever got to the major leagues. They all got traded—Rijo, McGee, McGriff, Drabek, Buhner. It just kept happening. It was all very frustrating and infuriating. We all thought we could run the team better than he could.”

That pain was worked into Seinfeld scripts easily and often. Quirky next-door neighbor Kramer, played by Michael Richards and based on David’s former real-life neighbor Kenny Kramer, once bounded into Seinfeld’s apartment and railed that Steinbrenner “is killing me” with his constant meddling, ticking off a similar list of prospects to the one David mentioned.

Kramer’s recounting of a bench-clearing brouhaha he started involving a different laundry list of team legends — Joe Pepitone, Moose Skowron, Hank Bauer, and more — while pitching at a Yankees fantasy camp also remains a hilarious scene. “Joe Pepitone or not, I own the inside of that plate,” Kramer said. “So I had to plunk him.” In the ensuing melee, Kramer unintentionally slugged and decked his hero — David’s, too — the great Mantle. “I looked down, and whoa man, it’s Mickey,” a distraught Kramer said. “I punched his lights out. So I got out of there.”

No matter, Costanza soon replaced Kramer as the character interacting most frequently with the storied franchise. He even wanted to name his first-born child “Seven” to honor The Mick. In the finale of Season Five in 1994, Costanza decided to ignore every impulse he has to do the opposite, a practice that immediately helps him pick up an attractive female patron at Monk’s Coffee Shop. The reversal soon also earned him an unlikely job interview with his favorite Bronx-based team. Costanza was introduced as a prospective applicant to Steinbrenner, who greeted him calmly enough by saying only, “Nice to meet you.”

“Well, I wish I could say the same, but I must say, with all due respect, I find it very hard to see the logic behind some of the moves you have made with this fine organization,” Costanza replied. “In the past 20 years, you have caused myself and the city of New York a good deal of distress, as we have watched you take our beloved Yankees and reduce them to a laughingstock all for the glorification of your massive ego.”

Steinbrenner emphatically responded: “Hire this man!”

And so began Costanza’s run as the Yankees’ assistant to the traveling secretary, a storyline that lent itself to the Seinfeld writers exploring how outlandishly they could go with their over-the-top parody of Steinbrenner. Seinfeld and David received The Boss’ approval to use his likeness and the Yankees’ brand.

“He thought we were making fun of him, thinking he was George Costanza. He didn’t know much about the show before we approached him. He didn’t realize that there already was this character named George for five years,” David said. “There must’ve been at least one big Seinfeld fan in his immediate family who told him he should do it.”

Indeed, Steinbrenner told Ira Berkow of The New York Times in 1996 that his grandchildren thought it was “cooler” that he was depicted in Seinfeld than “anything else I did in my life,” including owning the Yankees. And while Hal Steinbrenner described to me his own television viewing habits as “more of a History Channel and Discovery Channel buff than a sitcom guy,” George’s youngest son allowed that he and the rest of the family thought Seinfeld and their patriarch’s inclusion was “really very funny.” “That’s nice to hear,” David told me. “I’m glad they liked it at least.”

Even George Steinbrenner appreciated the humor after allowing his name and likeness to be used and lampooned throughout the series. “I was prepared not to like it, but I came away laughing my head off,” Steinbrenner told The Times. “Hey, if you can’t laugh at yourself, you’re in bad shape. We need more laughs today. I go to too many funerals and not enough birthday parties.”

Steinbrenner noted his favorite episode included the scene, in which he travels to Queens to the home of Costanza’s parents to erroneously inform them their son had died. George’s father, Frank Costanza, interrupted him and instead wanted to know: “What the hell did you trade Jay Buhner for? He had 30 home runs and over 100 RBIs last year. He’s got a rocket for an arm. You don’t know what the hell you’re doing!”

The fictional Steinbrenner replied, “Well, Buhner was a good prospect, no question about it. But my baseball people loved Ken Phelps’ bat. They kept saying ‘Ken Phelps, Ken Phelps.’ ” The kicker to the scene was Frank Costanza leaving a classic message on Seinfeld’s answering machine: “Jerry, it’s Frank Costanza, Mr. Steinbrenner’s here, George is dead, call me back!” The real-life Steinbrenner loved every bit of it. “It was sick, but hilarious,” Steinbrenner said.

“George Steinbrenner said that? I wasn’t even aware of that. That makes me smile,” David told me. “It’s pretty obvious I did not like that Jay Buhner trade one bit — and still don’t — I can tell you to this day.” The 23-year-old Buhner was traded to the Seattle Mariners in 1988 for Phelps, a 34-year-old designated hitter who totaled only 292 at-bats over parts of two seasons with the Yankees before he was dealt again to the Oakland A’s, where he earned a World Series ring in 1989 alongside Mark McGwire, Jose Canseco, and Tony La Russa. Buhner went on to belt 307 home runs in 14 seasons with the Mariners. “It’s great to be remembered for something, I guess,” Phelps joked about his Seinfeld mention when he and Buhner were reunited at Mariners spring training in 2015.

David didn’t initially intend to provide the voice for the Steinbrenner character, but it should be no surprise that it took two people to portray The Boss. An actor named Lee Bear played the physical version of Steinbrenner. Bear only was shown from behind, often flailing his arms maniacally, while David sat nearby off-camera and rambled about the Yankees and topics as diverse as calzones, cupcakes, and Cuban cigars. He once even butchered the lyrics to Pat Benatar’s “Heartbreaker.”

“I turned him into a bit of a nut,” David says. “It was just my sense of what he sounded like. That’s what he sounded like to me — that abrupt, staccato style he had. You know he would talk very quickly and very emphatically about things, just going on and on about different topics in different directions, kind of all over the place. I did my version of it for what we should be looking for, and Jerry said to me, ‘You know, you should just do it. It’s perfect.’ ”

The first pinstriped player to appear in the series was Danny Tartabull, who signed a five-year, $27 million contract with the Yankees as a free agent in 1992. He was traded to Oakland to conclude a largely disappointing Bronx tenure in 1995. Tartabull had cameos in two episodes in Season Six with then-manager Buck Showalter joining him in one appearance. George Costanza convinced Showalter that the Yankees should switch their uniforms from polyester, which was “not a natural fiber” to a more breathable cotton. “They’re more comfortable, they’re happier, they’re gonna play better,” Costanza told the nodding manager. Later in the episode, the plan blows up in Costanza’s face when the cotton uniforms shrunk and tightened on the players, prompting an announcer to exclaim: “Oh my God, Mattingly just split his pants!”

After David left the show following Season Seven, Williams and a young Jeter also took part in the episode shortly after the Yankees’ 1996 World Series title. Costanza extolled the two emerging stars on the art of hitting in the episode known as “The Abstinence,” in which he claims to be thinking clearer than ever because he’s abstaining from sex. “Guys, hitting is not about muscle. It’s simple physics,” Costanza explains as he cracks a few batting-practice pitches over the center-field wall at Yankee Stadium. “Calculate the velocity — V — in relation to the trajectory —T — in which — G — gravity, of course, remains a constant. It’s not complicated.” That leads to this memorable exchange:

Jeter: “Now, who are you again?”

George: “George Costanza, assistant to the traveling secretary.”

Williams: “Are you the guy who put us in that Ramada in Milwaukee?”

George: “Do you wanna talk about hotels, or do you wanna win some ballgames?”

Jeter: “We won the World Series.”

George, dismissively: “Yeah. In six games.”

The real Steinbrenner actually filmed one scene in front of the camera with Louis-Dreyfus for the Season Seven finale titled “The Invitations,” in which he volunteers to accompany her to Costanza’s wedding. David and Seinfeld ultimately decided not to use the scene, but someone had to tell The Boss. “It was much funnier just to see him from the back with my voice than to see him act, but I had to be the one to tell him that,” David said. “He said in that famous voice of his, ‘You can tell me. I can take it like a man.’ So I said, ‘Look, I’m sorry, Mr. Steinbrenner. We have to cut you from the show. I just wanted to let you know.’ He didn’t seem that disappointed about it. It just didn’t work.”

As for O’Neill’s Season Eight turn, Kramer promised a sick child in the hospital that the longtime right fielder would hit two home runs for him that night. Kramer was attempting to recoup a birthday card for Steinbrenner signed by the entire Yankees organization that he mistakenly sold to his friend, who dealt in sports memorabilia. “It’s terrible,” O’Neill said in the show. “You don’t hit home runs like that. It’s hard to hit home runs. And where the heck did you get two from?”

O’Neill scoffed when Kramer told him, “Babe Ruth did it.” Kramer then asked if he’s calling the Yankees legend a liar. O’Neill retorted: “I’m not calling him a liar, but he wasn’t stupid enough to promise two.”

Those cameos earned O’Neill some additional fame. “Honestly, I didn’t even know anything about the show. The first time I was asked, I said no. But these things only happen when you’re part of the New York Yankees,” O’Neill said. “They picked me up from Anaheim. They drove me over to the studio. We did the shots, and I remember I had a horrible game against Chuck Finley [of the Angels] that night. When it aired you don’t know how it’s going to come out. But even now you meet people, and some will tell you about a play or a game they remember. But just as many will tell me, ‘I remember you from Seinfeld.’ So that’s really cool.”

Eventually, even Costanza had enough of Steinbrenner. He tried to get himself fired late in Season Eight so he could take a better-paying scouting job with the Mets. He wore Babe Ruth’s uniform, rubbed strawberry juice on it, wore a nude-colored bodysuit, and streaked across the Yankee Stadium field. He even dragged the World Series trophy around the parking lot behind his car. But Costanza failed in getting fired. In the next episode, Costanza was traded to Tyler Chicken in exchange for a conversion of all stadium concessions to chicken-based products, including a beer substitute made of fermented alcoholic chicken.

This excerpt from “The Big 50: New York Yankees” by Peter Botte is printed with the permission of Triumph Books. For more information and to order a copy, please visit triumphbooks.com/Big50Yankees.