LAS VEGAS (AP) — Jon Jones will need an awfully good explanation for the latest major setback in his checkered mixed martial arts career.

Jones could be facing a multiyear suspension after the U.S. Anti-Doping Agency notified the UFC light heavyweight champion of a potential violation of the promotion’s anti-doping policy.

UFC President Dana White said Wednesday that the promotion likely won’t know for several weeks whether the test results will be confirmed after an examination of Jones’ backup sample. Any potential discipline must wait until after the adjudication process afforded to every fighter.

But unless some extraordinary reason surfaces for Jones’ latest failed test, the man widely considered the world’s best pound-for-pound fighter is facing another lengthy absence during his prime.

“At this point, who (cares) what I think? He’s done enough damage to himself,” White said while promoting Conor McGregor’s boxing showdown with Floyd Mayweather this weekend.

“His dad said it: Jon is his own worst enemy,” White added. “Boy, is that true. But sitting here today, it’s not over yet. He’s got to go through the process. Maybe there was something crazy that happened for this stuff to get into his system, so I don’t know.”

Jones has been provisionally suspended by USADA, which administers the UFC’s anti-drug policy. The California State Athletic Commission also has jurisdiction over Jones, who regained his light heavyweight title July 29 with a third-round stoppage of Daniel Cormier at UFC 214 in Anaheim. He failed a test conducted on a sample collected one day before the bout.

“If this holds up, and he ends up getting (a suspension of) two, three (years), it’s probably the end of his career,” White said.

Under its privacy rules, USADA won’t announce the substance for which Jones tested positive unless the fighter divulges it.

Jones’ agent, Malki Kawa, appeared on “The MMA Hour” podcast later Wednesday and said the fighter was told he had tested positive for turinabol, an anabolic steroid. Kawa said Jones passed two tests earlier in July, and the fighter is wondering whether he took a tainted nutritional supplement in the weeks before the bout.

Kawa posted a strident defense of his client on Facebook on Wednesday.

“I know how hard he worked to get back to where he’s at,” Kawa wrote. “This is definitely heartbreaking. He (definitely) didn’t cheat or use steroids. But I’m with him more now than the night he won the belt.”

Jones hasn’t publicly commented on the third failed test of his career.

He tested positive for cocaine in 2015, later publicly acknowledging he had used the drug. He then received a yearlong suspension in 2016 for what he claimed was a sexual enhancement pill. His fight against Cormier was his first since that suspension ended.

Penalties are compounded for multiple failed tests, and a multiyear suspension would leave the UFC without one of its rising pay-per-view draws. Jones’ bad-boy image actually appears to have made him more marketable for the UFC, which has a current dearth of pay-per-view stars.

Brock Lesnar, Ronda Rousey, McGregor and Georges St. Pierre are all in various stages of retirement, comebacks or more lucrative side jobs, with only St. Pierre currently scheduled for an MMA fight.

Jones’ mistake also throws two weight classes into upheaval.

White said Cormier is likely to regain the UFC light heavyweight title, which he held twice after Jones was stripped of the belt for his first two failed tests. Cormier also reigned atop the division while Jones was sidelined following his arrest over a hit-and-run accident.

Cormier has never lost to anyone but Jones, but the good-natured star will be in the same awkward position in which he found himself during Jones’ previous forced absence.

And Jones appeared to be ready to make an impact on the UFC heavyweight division. White had been talking to Jones’ camp about matching him with heavyweight champion Stipe Miocic in Detroit later this year in what would have been a blockbuster pay-per-view matchup.

Instead, Miocic must find a new opponent for his belt — and any matchup that the UFC can make will be less intriguing than a showdown with Jones.

“We’ve got a lot of problems if this turns out to be true, but they aren’t problems compared to what Jon has,” White said. “The list goes on and on of what could have been with Jon Jones.”