LAS VEGAS — Brock Lesnar is working his way back into UFC compliance.

The former UFC heavyweight champion has started the process to get back in the USADA drug-testing pool, an agency spokesperson confirmed with MMA Fighting on Saturday night. UFC president Dana White first mentioned it at the UFC 226 post-fight press conference.

Lesnar was called out by new UFC heavyweight champion Daniel Cormier after Cormier defeated Stipe Miocic in the UFC 226 main event here at T-Mobile Arena. When Lesnar is officially back in the drug-testing pool, he’ll still have a little more than six months left of his previous suspension, which means he would not be able to enter the Octagon until at least January.

Per the UFC anti-doping policy, when a fighter under suspension retires, that suspension remains frozen until a fighter re-enters the drug-testing pool. Lesnar formally retired about six months into his one-year suspension, which was the result of his testing positive for the banned substance clomiphene in multiple drug tests in relation to UFC 200 in July 2016.

The USADA spokesperson was not able to go into detail as to what Lesnar has done so far regarding beginning the process. MMA Fighting tracked down Lesnar backstage at T-Mobile Arena as he was leaving the building Saturday and he ignored questions about being back in the drug-testing pool.

After Cormier beat Miocic, he called out Lesnar, who was sitting cageside — his first time at a UFC event since UFC 200. Lesnar entered the Octagon and shoved Cormier and a scuffle — and some trash talk — ensued between both sides.

Lesnar, who came up as a decorated amateur wrestler like Cormier, is a current member of the WWE roster and the promotion’s Universal Champion. He has not wrestled for WWE since April.

White said Saturday that Lesnar’s deal with WWE allows him to fight in the UFC.