For 21 tumultuous months, New York Yankees superstar Alex Rodriguez has defiantly maintained he never used banned substances from a Coral Gables anti-aging clinic, that he was the victim of a “witch hunt,” that his suspension from baseball was unjust and that he would fight to the end to clear his name.

But in a Weston conference room back in January, facing federal drug agents and prosecutors who made him swear an oath to tell the truth, baseball’s highest-paid player admitted everything:

Yes, he bought performance-enhancing drugs from Biogenesis of America, paying roughly $12,000 a month over about two years to fake doctor Anthony Bosch. Yes, the Biogenesis owner gave him pre-filled syringes for hormone injections into his stomach, and even drew blood from him in the men’s room of a South Beach nightclub. And yes, Rodriguez’s cousin, Yuri Sucart, was his steroid go-fer.

In exchange for coming clean behind closed doors, Rodriguez got immunity from prosecution.

Publicly, however, he never veered from his I-am-innocent narrative.

Less than three weeks before his date with the prosecutors and the Drug Enforcement Administration, an arbitrator reduced his Major League Baseball suspension from 211 to 162 games. Rodriguez indignantly declared: “I have been clear that I did not use performance-enhancing substances … and in order to prove it, I will take this fight to federal court.”

Joseph Tacopina, the attorney who represented Rodriguez at the meeting with prosecutors and the DEA, declined to comment on his client’s about-face, citing the need to maintain grand jury secrecy.

The Miami Herald reviewed a 15-page synopsis of Rodriguez’s meeting with the feds, which took place Jan 29.

It is his never-before-revealed confession.

According to the DEA’s “report of investigation,” Rodriguez used substances prohibited by Major League Baseball from late 2010 to October 2012. He admitted getting testosterone cream, lozenges laced with testosterone (aka “gummies”) and human growth hormone injections.

“Rodriguez said Bosch told him the HGH would help with sleep, weight, hair growth, eyesight and muscle recovery,” the report stated.

It also noted that Bosch, who pretended to be a doctor even though he wasn’t one, “injected Rodriguez in the buttocks with a red liquid substance.” He told Rodriguez the liquid was “vitamins, not testosterone.”

In total, the report said, Bosch injected Rodriguez with the “vitamin cocktails” five to 10 times.

Rodriguez also described how Bosch gave the ballplayer “tips on how to beat MLB’s drug testing,” the DEA report said.

The secret? According to Rodriguez, “Bosch advised him to only use mid-stream urine for MLB drug testing. Bosch told Rodriguez not to use the beginning or the end urine stream.”

It worked. During the American League Championship Series against the Detroit Tigers, Rodriguez was called to take a drug test. He passed. The Yankees were swept in the series.

Rodriguez’s DEA statement would fortify the criminal steroid case against Bosch, the owner of now-closed Biogenesis, and his network of South Florida suppliers and distributors. Rodriguez would also implicate the “middleman” — his cousin Sucart — who introduced him to Bosch, “discussed price, arranged pickups for PES [performance-enhancing substances] and delivered money to Bosch on Rodriguez’s behalf,” the DEA report said.

Since criminal charges were filed in August against Bosch, Sucart and five others, four defendants — including Bosch have pleaded guilty. Sucart, who has admitted nothing but was caught on wiretaps discussing and buying steroids, “fully plans on going to trial” in February, said his attorney, Edward J. O’Donnell IV.

Prosecutors plan to use Rodriguez’s testimony against Sucart if he doesn’t cut a plea deal before trial, prosecutors Pat Sullivan and Sharad Motiani wrote in court papers.

Biogenesis’ customers included not just MLB players but also high school athletes, police officers, a few federal agents and a state circuit court judge. Some of those customers, including Rodriguez, were outed as Bosch’s clients in a Miami New Times exposé on the steroid clinic published in late January 2013. There are no plans to prosecute any of them.

Besides Rodriguez, prosecutors granted “direct immunity” to a total of eight current and former professional players: Ryan Braun; Melky Cabrera; Nelson Cruz; Francisco Cervelli; Yasmani Grandal; Cesar David Puello; Jordany Valdespin, and Manny Ramirez. Direct immunity means their statements can’t be used against them in the Biogenesis criminal case.

In all, 14 ballplayers were suspended by Major League Baseball for their links to the now-shuttered clinic.

Rodriguez, 39, a onetime Miami-Dade high school standout and University of Miami benefactor whose name is on UM’s Coral Gables baseball stadium, received the longest suspension. He was reinstated to the Yankees after the 2014 World Series.

Whether the aging star can play anywhere near his old standard remains to be seen. He has two surgically repaired hips and hasn’t played organized baseball in a year. Rodriguez is still owed $61 million by the ball club for the three years left on his $271 million contract, baseball’s largest.

Rodriguez had been on the league’s radar for steroid abuse since 2009, when he admitted that he had used performance-enhancing substances as a member of the Texas Rangers in 2001-03 and fingered Sucart as his conduit back then. After that disclosure, Sucart was banned from associating with anyone involved in professional baseball.

According to Rodriguez’s statement to DEA agents, in summer 2010 he had gained some weight and was experiencing some “problems” with injuries to his knee.

He wanted to lose five to 10 pounds. Sucart, a man of considerable girth, told him he himself had lost some weight with the help of a South Florida “doctor.” Sucart said the man — he didn’t name him — could help Rodriguez get into better shape.

“Sucart told Rodriguez that the doctor was a smart guy and a guru,” the DEA reports said. “Rodriguez stated that Sucart was very aggressive and persistent about Rodriguez meeting the doctor.”

Then, later that summer, Sucart told Rodriguez that the “doctor” would be in Tampa at the same time as the two of them and arranged a meeting in Rodriguez’s hotel room. The man introduced himself as “Dr. Tony Bosch.” Although Bosch graduated from a medical school in Belize, he was not licensed to practice medicine in Florida. In addition to Sucart, also present at the meeting was one of Bosch’s steroid suppliers, Jorge Velazquez, from Miami.

“During the meeting, Bosch told Rodriguez that he treated hundreds of baseball players,” according to the DEA report. “Bosch told Rodriguez that [former Los Angeles Dodgers and Boston Red Sox outfielder] Manny Ramirez was one of his clients. Bosch took credit for how well Ramirez performed in baseball.”

Ramirez, who is no longer playing in the majors, was one of the best hitters of his generation. At the time of that discussion, he had been exposed as a steroid cheat, having been suspended in 2009 for 50 games after testing positive.

Bosch said Ramirez got caught because he didn’t follow Bosch’s “protocols.”

Bosch, who referred to himself as a “wizard,” told Rodriguez that he could help him lose weight, reduce his pain from injuries and increase his energy. Bosch examined Rodriguez in the hotel room and told Sucart that the ballplayer was “fat.” Bosch said he wanted to run tests of his blood to check his testosterone levels.

“Bosch told Rodriguez he would protect Rodriguez’s name,” the DEA report said. “When Bosch did draw Rodriguez’s blood, Bosch told Rodriguez he would send the blood to the laboratory for analysis under a fictitious name.”

The name Bosch chose was a code name, “Cacique.” The term derives from the Spanish-speaking Caribbean, roughly translating to “local chieftain.”

Rodriguez told DEA agents that from late summer 2010 to October 2012, Bosch drew his blood about 10 times in South Florida, Tampa and New York. Rodriguez also confirmed that Bosch drew Rodriguez’s blood in the bathroom of the LIV nightclub in Miami Beach, just as Bosch would later claim in a 60 Minutes news segment.

Bosch told the ballplayer that his “testosterone levels were low for a man of his age.”

Finally, the DEA report said, “Bosch told Rodriguez he was not a rat and would not break if he was ever approached by MLB or anyone else.” It was a promise that Bosch would break in 2013, when major-league officials sued him and others, while federal authorities stepped up their steroid investigation.

Rodriguez ordered the drugs through Sucart, who would receive and send text messages between the ballplayer and Bosch. Sucart’s role would end, however, in April 2012, after the two had a falling out over money.

After that, Rodriguez and Bosch would deal with each other directly.

To pay his drug dealer, Rodriguez would either write personal checks to “cash” — to avoid any paper trail — or he would request “petty cash” from the Yankees’ team secretary, the report said.

Bosch turned on Rodriguez after the Miami New Times published the bombshell story in early 2013 on his anti-aging clinic’s sale of banned substances to major leaguers. He became a cooperating witness who helped Major League Baseball secure the suspensions of 14 ballplayers — including Rodriguez, a three-time American League Most Valuable Player, and Braun, the 2011 National League MVP. In exchange for Bosch’s cooperation, MLB paid for his costly criminal defense.

Most of the suspended players, including Braun, have given sworn statements to DEA agents and prosecutors.

As the government ratcheted up the pressure, onetime allies Rodriguez and Sucart became enemies. Rodriguez told DEA agents that Sucart sent him an “extortion letter,” demanding $5 million so that he “would not disclose Rodriguez’s relationship with Bosch,” the DEA report said. Rodriguez visited with “his friend,” prominent Miami criminal defense attorney Roy Black, seeking advice.

Ultimately, Rodriguez agreed to pay Sucart $900,000. Sucart was also allowed to keep his southwest Miami-Dade home and Chevy Suburban SUV, both bought for him by Rodriguez.

Miami criminal defense attorney Frank Quintero, who is representing a co-defendant accused of conspiring with Bosch to distribute steroids to high school athletes, said the government’s immunity deal with Rodriguez was a “farce” in light of his alleged crimes — including bribery, tampering with witnesses and obstruction of justice.

“The immunity given to Rodriguez and these other ballplayers is an attempt by the Justice Department to cover up their alleged crimes,” Quintero said. “MLB committed the same alleged crimes that these ballplayers did by bribing witnesses, interfering with the state and federal investigations and obstructing justice.”