Just one day after reports of his next fight surfaced, former UFC Heavyweight Champion Fabricio Werdum is looking at a suspension.

As reported by MMA Fighting, the UFC announced on May 22 that Werdum was flagged for a potential anti-doping violation. Werdum failed an out-of-competition drug test conducted by the U.S. Anti-Doping Agency (USADA) on April 25.

In a statement, the UFC said, “USADA, the independent administrator of the UFC Anti-Doping Policy, will handle the results management and appropriate adjudication of this case involving Werdum.

Under the UFC Anti-Doping Policy, there is a full and fair legal process that is afforded to all athletes before any sanctions are imposed.”

Werdum's ups and downs

Werdum took to his Instagram to plead innocence, claiming he did not take anything illegal and the situation is a misunderstanding.

But he will now be suspended until the USADA matter clears up, if not for longer.

Werdum won the UFC Heavyweight Championship back at UFC 188 in June 2015, extending his then win streak to six. He lost the title to Stipe Miocic in his first defense at UFC 198 back in May 2016. Since then, Werdum has gone 3-2 inside the Octagon.

Most recently, Werdum competed in the main event of a UFC Fight Night back in March, losing in upset fashion to Alexander Volkov after getting knocked out in the fourth round.

This loss snapped a pair of back-to-back victories for Werdum, who defeated Walt Harris at UFC 216 in October and Marcin Tybura at UFC Fight Night 121 one month later.

Plans for UFC in Russia

MMA journalist Ariel Helwani originally reported on May 21 that Werdum’s next fight would likely be a headline bout against Alexey Oleynik on September 15 at UFC Fight Night 136 in Moscow.

It will be the UFC’s first-ever event to take place from Russia, Oleynik's home country.

The promotion never officially confirmed the bout between the grappling and submission experts.

Oleynik defeated Junior Albini at UFC 224 with an Ezekiel choke, the 12th win of his professional career via the submission hold.

The UFC has been trying to break into Russia for some time now.

Initial hopes from several members of the MMA community and fandom was a pay-per-view card headlined by current UFC Lightweight Champion Khabib Nurmagomedov taking on Conor McGregor.

The event will instead be a UFC Fight Night — either aired on TV or UFC Fight Pass. Oleynik, at least for now, is expected to remain on the card in the headline spot.