Oscar De La Hoya lost his own boxing match with Floyd Mayweather in 2007. (Andrew Estey/Invision/Associated Press)

The long-discussed fight between Floyd Mayweather and Conor McGregor appears closer than ever to becoming a reality, and Oscar De La Hoya is not happy about it. The former champion boxer, now a major fight promoter, posted an open letter Thursday in which he slammed the high-profile matchup as a “circus” that would hurt his sport.

Describing himself as among the “fans” of boxing, “who are the lifeblood of our sport,” De La Hoya used his Facebook page to argue that boxing “might not ever recover” from “this farce.” His point was that in a boxing rules-only match, McGregor stood no chance against a former five-division world champion who retired undefeated and is considered to be arguably the finest defensive tactician of all time.

Thus fans would be shelling out hefty sums for a fight that would completely fail to justify its considerable hype, leaving them disillusioned with boxing, much as they were after Mayweather’s desultory win over Manny Pacquiao in 2015. “Boxing is starting to dig out of the hole that Floyd and Manny Pacquiao shoveled by waiting seven years to put on a fight that ended up being as dull as it was anti-climactic,” De La Hoya said.

“If you thought Mayweather/Pacquiao was a black eye for our sport — a matchup between two of the best pound-for-pound fighters that simply didn’t deliver — just wait until the best boxer of a generation dismantles someone who has never boxed competitively at any level — amateur or professional,” the “Golden Boy” told his Facebook audience.

McGregor is applying for a boxing license in Nevada, ahead of a lucrative event that would almost certainly be staged in Las Vegas, and he has posted multiple videos showing him training in the sport. However, despite the punching power he has displayed while winning the UFC featherweight and lightweight belts, the Irishman has been installed in Vegas sports books as a massive underdog.

While praising McGregor, 28, as “almost certainly the best pound-for-pound MMA fighter,” De La Hoya called Mayweather, who defeated him by split decision in 2007, “the most dominant boxer of his time.” He noted that “success in one sport does not guarantee success in another,” and said the fight would be like himself, as “a pretty good golfer,” trying to “compete with Rory McIlroy, Jordan Speith or Sergio Garcia.”

De La Hoya also acknowledged that his objections to the fight could be construed as sour grapes from a promoter with a strong interest in the success of another highly anticipated boxing match set to take place later in the year. He is a promoter for Canelo Alvarez, who will take on Gennady Golovkin in a megafight that could lose revenue to fans saving their pay-per-view dollars for Mayweather-McGregor.

De la Hoya, though, claimed that his “interest is in the health of boxing as a whole,” and “always has been.” He said that if Mayweather “were to come out of retirement to take on someone like Keith ‘One–time’ Thurman, Errol Spence or some other top welterweight,” he would “be the first one on line for a ticket.”

However, De La Hoya said, it is apparent that Mayweather, 40, is only returning to the ring for “money,” which is also McGregor’s “motivation” for the fight. It would be hard to argue with De La Hoya on that point — both of the would-be combatants, particularly Mayweather, have essentially said that, as well.

The problem with both Mayweather and McGregor being guaranteed to make a fortune off their showdown is “a lack of consequences for when the fight ends up being the disaster that is predicted,” De La Hoya said. “After this fight, neither of them will need us anymore. Floyd will go back to retirement — presumably for good this time with another nine-figure paycheck — and Conor will go back to the UFC.”

The outcome could be even more dire than that for combat-sports fans, if, as UFC president Dana White has warned, McGregor decides his huge payday means he doesn’t have to return to MMA. “Conor could make $75 million; how do you come back and fight [for] $10 million? He may never fight again,” White said this week. “You have to be hungry, and you may not be hungry with $75 million in the bank, but he is hungry for Mayweather and hungry to prove people wrong.”

In that case, the only hope MMA fans have for seeing McGregor in the Octagon again might be to take De La Hoya’s advice and make common cause with boxing fans in boycotting Mayweather-McGregor. “At this point, only we can shut the circus down by making it clear that we won’t pay to see a joke of a fight,” he said on Facebook, “and telling our casual-fan friends that they shouldn’t either.”