Floyd Mayweather punches Manny Pacquiao during their May fight, won by Mayweather. (Steve Marcus/Reuters)

On Saturday, Floyd Mayweather will face Andre Berto in what he has repeatedly insisted will be his final fight. However, long after that event, the undefeated welterweight could continue to have questions asked of him about what took place before his fight with Manny Pacquiao, and about his relationship with the U.S. Anti-Doping Agency.

According to a report by Thomas Hauser of SB Nation, Mayweather received two intravenous injections, adding up to 750 milliliters of fluid, the day before the May 2 fight, which he won by unanimous decision in Las Vegas. The fluids that the boxer’s camp said were in the injections, mixtures of saline solution and vitamins, would not have been inherently illegal, but the quantity, in that time frame, could have masked another substance and would have been in violation of rules set forth by the World Anti-Doping Agency.

Furthermore, representatives of USADA, which is supposed to abide by WADA rules, became aware of the injections when they went to administer a drug test to Mayweather, but the agency failed to report the incident to the Nevada State Athletic Commission, which sanctioned the fight. The NSAC was only made aware of the injections nearly three weeks after the bout, and even then, USADA claimed that it had granted Mayweather a Therapeutic Use Exemption (TUE), basically a get-out-of-jail-free card, which some experts quoted by Hauser found very odd, at the very least.

Victor Conte, who gained notoriety as a peddler of performance-enhancing drugs in the Bay Area Laboratory Co-Operative case, but who has since become an anti-PED advocate, had this to say:

“There are strict criteria for the granting of a TUE. You don’t hand them out like Halloween candy. And this sort of IV use is clearly against the rules. … It’s very suspicious to me. I can tell you that IV drugs clear an athlete’s system more quickly than drugs that are administered by subcutaneous injection. So why did USADA make this decision? Why did they grant something that’s prohibited?”

Bob Bennett, who has been executive director of the NSAC since April 2014, and who was previously an FBI agent, told Hauser, “The TUE for Mayweather’s IV — and the IV was administered at Floyd’s house, not in a medical facility, and wasn’t brought to our attention at the time — was totally unacceptable.”

Floyd Mayweather speaks at a news conference promoting his fight with Andre Berto. (AP Photo/John Locher)

Other concerns raised by the lengthy report for SB Nation include:

  • The USADA, a non-governmental agency that receives about $10 million in annual funding from Congress, appeared to have given favorable treatment to some boxers, including not just Mayweather but Erik Morales, who in 2012 tested positive for a PED and reportedly failed several more tests, although the New York State Athletic Commission was not informed of the failed tests in a timely manner.
  • Mayweather’s camp has claimed that the fighter is subject to testing “365-24-7 by USADA,” but in reality, he determines when the testing period begins. In the case of the Berto fight, that began when the event, which had been rumored for weeks, was officially announced in early August, by which point Mayweather potentially could have undergone an assortment of treatments following the Pacquiao bout.
  • As Conte put it, “I can’t tell you what Floyd Mayweather is and isn’t doing. What he could be doing is this. The fight is over. First, he uses these drugs for tissue repair. Then he can stay on them until he announces his next fight, at which time he’s the one who decides when the next round of testing starts. And by the time testing starts, the drugs have cleared his system.”
  • The drug-testing contract with USADA agreed to by Mayweather and Pacquiao provided for exceptions to WADA rules.
  • In 2012, Pacquiao’s camp rejected a proposed contract clause that could have allowed USADA to grant a retroactive TUE without notifying the NSAC or the other fighter.
  • In tests administered to Mayweather by the NSAC for fights in 2011 and 2013, he posted unusually low testosterone-to-epitestosterone ratios, either of which, as another expert described to Hauser, should have served as “a warning flag” for doping.
  • Another anti-doping agency, VADA, charges less than USADA and offers more stringent tests.
  • In 46 fights for which it has done testing, USADA acknowledged just one boxer caught with PEDs (Morales), whereas VADA had found three positive results in 18 fights.

Among the fighters VADA flagged for PED use was Berto, in 2012.