UFC vice president of athlete health and performance Jeff Novitzky told Raimondi that Lesnar had not re-entered the pool.
Earlier, Ryan Satin of Pro Wrestling Sheet reported Lesnar has re-entered the USADA testing pool for MMA after exiting when he formally announced his retirement from the sport in February.
Lesnar would have five months remaining on the one-year suspension he was handed for twice testing positive for performance-enhancing drugs around his UFC 200 fight with Mark Hunt. He informed UFC of his retirement—and, thus, was taken out of the USADA testing pool—in February.
"Pursuant to the UFC Anti-Doping Policy, all UFC athletes serving a period of ineligibility for an anti-doping policy violation are required to remain in the USADA registered testing pool and make themselves available for testing in order to receive credit for time served under his or her sanction," a USADA press release said.
"Furthermore, if an athlete retires during his or her period of ineligibility, the athlete's sanction will be tolled until such time the athlete notifies USADA of his or her return from retirement and once again makes him or herself available for no-advance-notice, out-of-competition testing."
Satin's report indicates Lesnar has no plans at this time of re-signing with WWE once his contract expires shortly after WrestleMania 34. The two sides held tense negotiations when Lesnar first flirted with returning to MMA when his WWE contract expired in 2015. He ultimately wound up re-signing with the wrestling promotion for three more years.
WWE accommodated Lesnar's return to UFC last year in a cross-promotional event, but it's unlikely the company would want him doing potentially dangerous combat sports when he's under contract. If Lesnar's serious about a return to UFC sometime in 2018, odds are these rumors are true.
Given his status as Universal champion, it's probably time to start the clock ticking on him dropping the belt.