Brock Lesnar has been subjected to his first drug test since putting the wheels in motion to make a return to the UFC for a heavyweight title fight with Daniel Cormier.

Lesnar (5-3 MMA, 4-3 UFC), a former UFC heavyweight champ and current WWE Universal titleholder, will not be eligible to compete inside the octagon until Jan. 8, 2019, after he serves the final six months of his current U.S. Anti-Doping Agency (USADA) suspension. That six-month period coincides with the testing period an athlete coming out of retirement must serve before fighting.

After re-entering the testing pool on July 3, Lesnar provided his first sample to USADA this week, according to the latest update on the “Athlete Test History” section of the company website.

The results have yet to be revealed, but Lesnar must pass all tests if he wants to fight in the UFC again and bring the matchup with Cormier (21-1 MMA, 10-1 UFC) to fruition.

After months of speculation, Lesnar made his return to the UFC scene earlier this month when he popped up cageside in Las Vegas for the UFC 226 headliner between Cormier and Stipe Miocic. “DC,” who is also the light heavyweight champion, won by first-round knockout to become just the second dual-titleholder in company history.

Immediately following the fight, Cormier, 39, invited Lesnar, 41, into the octagon for a face-to-face. Absolute chaos ensued, marking the start of a build for planned heavyweight showdown between the two.

Lesnar hasn’t competed in MMA since UFC 200 in July 2016. He defeated Mark Hunt at the event, but the result was later overturned when Lesnar flunked multiple drug tests around the time of the fight. He was issued a one-year suspension from USADA, but the timeframe was frozen roughly six months in when he announced his retirement from fighting.

Two years later Lesnar is back, and his test results will be under a microscope. Cormier said he wasn’t going to agree to the title defense unless he’s 100 percent positive of a “clean” fight with a level playing field.

“Brock’s got to be clean,” Cormier said. “I’m not going to fight him if he’s not clean. We’ll do USADA testing, and we’ll do other testing. We’ll do testing above USADA to make sure this man’s clean, because I’m not going to fight him if he’s cheating. I’ve done that on a number of occasions already (with others). I don’t want to fight him if he’s dirty, man. Do it the right way.”

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