Arizona State standout Reggie Jackson was considered the best amateur ballplayer in the country heading into the 1966 Major League Baseball draft. The team picking first that year was the lowly, awful New York Mets.

According to Jackson’s new tell-all, “Becoming Mr. October” (Doubleday), in which he details feuds and resentments toward his old Yankee teammates, the New York media and especially his old manager Billy Martin, the only reason he did not become a Met was because his girlfriend, Juanita Campos, was Hispanic.

Jackson recalls how his coach at Arizona State, Bobby Winkles, broke the bad news.

“A day or two before the draft, Bobby Winkles sat me down and told me, ‘You’re probably not gonna be the No. 1 pick. You’re dating a Mexican girl, and the Mets think you will be a problem,’ ” Jackson writes. “ ‘They think you’ll be a social problem because you are dating out of your race.’ ”

Jackson was especially baffled because he’s part Hispanic — his grandmother is from Puerto Rico and his middle name is Martinez. But that didn’t matter, even to the perennial cellar-dwelling Mets.

“No, you’re colored, and they don’t want that,” Winkles said.

‘Becoming Mr. October” is a score-settling lament about all the people who have wronged Jackson, who comes off as the A-Rod of his day — incredibly talented, disliked by his teammates and ignorant of why anyone would be mad at him.

“This book has been written because I wanted to set the record straight regarding what the 1977-1978 seasons of the Yankees were like from my side,” Jackson writes. “The mini-series ‘The Bronx is Burning’ thoroughly embarrassed me the way the story was told.”

Throughout the book, Jackson writes almost wistfully about other teams he could have played for, as if any life path would have been better than the one that led him to The Bronx.

The MVP of the 1973 World Series as an outfielder for the Oakland A’s, which beat the Mets that year, Jackson imagines how the Mets might have won the series if he’d been on that team instead.

He blamed the Mets’ infamous draft-day decision on Bob Scheffing, the team’s director of player development. According to Jackson, he was also the guy who would later trade Nolan Ryan. But Scheffing tried to pass the blame on to Casey Stengel, who was scouting for the team at the time.

“I know I never saw Casey Stengel when I was being scouted,” writes Jackson. “And how could you be in a ballpark and not know if Casey Stengel was there?”

Jackson wishes he could have been directly inspired by Mets’ veterans and managers of that era, including the late Gil Hodges, whose team won the 1969 World Series, and Yogi Berra, who managed the overachieving 1973 squad. “Unlike Billy Martin, Yogi didn’t need to be the star all the time,” he notes. “He already was the star.”

His desire to have been a Met comes off as almost romantic. “I think about that sometimes. I would’ve been coming up just as that team was finally improving. They had all those great arms: Tom Seaver, Jerry Koosman, Jon Matlack, Nolan Ryan, Tug McGraw. Oh boy!”

Free agency came into play in the mid-’70s, and Jackson hoped to wind up on the Dodgers, gushing for a full page about the prospect of playing for Dodgers manager Tommy Lasorda and alongside the likes of Steve Garvey and Davey Lopes.

But the Dodgers didn’t make an offer following the 1976 season, and after Yankee owner George Steinbrenner wined and dined him at the “21” Club, then strategically walked him through the streets of New York knowing that fans would scream encouragement to the star. Jackson wound up a Yankee — and his problems began almost immediately.

For a televised competition between the Yankees and the Cincinnati Reds — the past season’s World Series teams — Jackson flew to Hawaii with several of his new teammates, including Chris Chambliss, Graig Nettles, Sparky Lyle and Roy White.

According to Jackson, his new teammates “didn’t give me the time of day.” When asked by the press about the trip, he called it “uncomfortable.”

Catcher Thurman Munson, he writes, was jealous because Jackson — baseball’s highest-paid player after he signed with the Yanks — made more money than him.

It was Munson who coined Jackson’s immortal nickname — but he was being sarcastic. After Billy Martin had Catfish Hunter start a game during the 1977 World Series after a month-long layoff with an injured arm, Jackson slammed him to the press, saying, “How do you make a decision like that?” Steinbrenner had Jackson publicly apologize, and it was during this battle that Munson, taking Martin’s side, said, “Billy probably just doesn’t realize Reggie is Mr. October.”

But Jackson lived up to the moniker, earning series MVP honors for the second time in his career by batting .450 with five homers including three in one game, a feat previously accomplished by only one man, Babe Ruth.

Third baseman Nettles also cut Jackson down in the press. “Graig Nettles had a very witty sense of humor, but it often had a very negative slant to it,” he writes. “He liked to say, ‘The best thing about playing for the Yankees is you get to see Reggie Jackson play every day. The worst thing about playing for the Yankees is you get to see Reggie Jackson play every day.’”

Relationships with many of his teammates remained sour, and he notes that of the team’s black players, only Willie Randolph reached out. “The rest . . . I felt they were always supporting the other side. I couldn’t understand it. Most of the black players on our team did not support me, and that hurt.”

More hurtful, writes Jackson, is that not one of his teammates wanted to take the locker next to his.

At one point, someone on the team — he never learned who — even placed a note in the pants pocket of his uniform that read, “Get your f—ing ass out of here.”

But the cold indifference or bitter sentiment of his teammates paled compared to the blind hatred he felt from hard-drinking manager Billy Martin, a contempt that Jackson quickly returned.

Jackson recounts a litany of Martin’s evils, including anti-Semitism Martin directed toward a player Jackson doesn’t name but who is clearly Yankee pitcher Ken Holtzman.

“I was standing near the bat rack early in spring training, and I heard some of the worst anti-Semitic remarks and jokes directed at one of our own players. This went on far too often,” writes Jackson. “When this player was pitching and doing well, he was ‘the great lefty.’ When he wasn’t, it was the name of his ethnic group and religion, ‘the Jew.’ ”

Jackson also cites Martin’s flat-out racism toward him. During a meeting general manager Gabe Paul arranged to settle a dispute between the two, Jackson says that Martin showed up a half-hour late, with alcohol on his breath, at 8:30 a.m.

As Jackson presented his side, Martin suddenly interrupted him in a rage.

“Right away, Billy’s furious,” Jackson writes. “He stood up and looked at me, and he said, ‘Get up, boy! I’m gonna kick the s–t out of you!’ ”

Paul told Martin that he was out of line, but the manager suffered no consequences.

Martin was violent toward players in the most cowardly ways, Jackson claims.

In one early incident, Martin, who Jackson pegs as weighing 155 pounds soaking wet, blindsided a player named Dave Boswell “when he had his hands in his pockets.”

Just after reliever Goose Gossage joined the Yankees in 1978, they played a spring-training game against the Texas Rangers. Gossage was about to pitch to a rookie outfielder named Billy Sample when Martin told him, “Hit this blankety-blank in the head” for no apparent reason.

Gossage refused, telling him, “Sample never did anything to me. I’m not gonna fight your fights,” then added, “I hit Sample in the head, I could kill him.” Martin replied, “I don’t give a s–t if you do kill him!”

“He called Gossage every name in the book. A really vile tirade,” Jackson writes. “Martin never got over him refusing to hit Sample during a spring-training game. From then on, Goose and Billy had no relationship.”

His criticisms of Martin extend past personal failings to his strategic acumen, with Jackson claiming that Martin destroyed the arms of his pitchers wherever he managed, citing Cy Young winners and Yankee teammates Hunter and Lyle as two who were never the same after Martin thoughtlessly overused them.

In time, the perpetual animosity between Jackson and Martin comes off with all the maturity of two kids fighting over a toy.

One of their earliest battles occurred because both felt the other should have made the introductory phone call after Jackson was signed. After noting that Martin never called him in the 1976-77 off-season to welcome him — a call he claims is standard for managers — word filtered back that Martin was offended that Jackson didn’t call him.

Martin began trashing Jackson in the press by the season’s second week, reacting to a Jackson error that led to a 3-2 loss by calling him a “bad defender.”

Increasingly, Martin derived personal glee from humiliating his star free agent. After a ball dropped between Jackson and second baseman Randolph during a game, Martin went to the mound to make a pitching change.

Both the pitcher, Mike Torrez, and Munson later said that as he did, he told Torrez, “Watch this . . . I’m gonna go get that son of a bitch,” then shocked Jackson by removing him from the game as well.

The screaming that followed between the two on the dugout steps concluded with Jackson telling him, “You are not a man,” Martin threatening to kick his butt by replying, “I’ll show you whether I’m a man or not,” and Jackson saying, “If you think you’re gonna kick my butt, you must be crazy” as he walked away.

“He knew he was acting. He didn’t want to take me on,” Jackson writes. “It would’ve been like ordering an ice-cream cone and getting a whole gallon.”

Throughout his Yankee tenure, Jackson was perplexed and hurt by his manager’s animosity.

“I thought, I’m playing hard for you,” he writes. “Why don’t you like me?”

Jackson never got his answer. Together, the two helped lead the Yankees to a 1977 World Series win but at the cost of emotional scars that Jackson clearly carries to this day.

The Yankees won the Series the next year too, but Martin was fired mid-season, partly because of his feud with the slugger.

“Billy Martin was a human tragedy, in the real sense of the words,” he writes.

Jackson was inducted into Baseball’s Hall of Fame in 1993, but Martin didn’t live to see it. He died on Christmas Day 1989, in a single-vehicle accident on an icy road.

He was buried in upstate Hawthorne, just a few hundred feet from the Yankee great Babe Ruth.