The plot thickens.

According to a story from USA Today’s MMA Junkie blog, the UFC strongly denies reports that WWE Universal champion Brock Lesnar is back in the United States Anti-Doping Agency (USADA) testing pool, which would be a requirement for Lesnar to participate in a professional fight with the company.

Moreover, if Brock intends to come out of his mixed martial arts retirement he needs to inform UFC of that intent so he can be tested for “at least six months before returning to competition”. Neither the testing or the notification have occurred, per UFC Vice President of Athlete Health and Performance Jeff Novitzky.

Novitzky told MMAJunkie there is “zero truth” to reports the former UFC Heavyweight champion has taken that first step toward a comeback:

[Lesnar] is not currently enrolled in the USADA testing pool, nor has there been any inquiry on his part to do so.

While this is counter to reports from earlier today, it doesn’t necessarily mean Lesnar won’t use a return to MMA and the UFC as leverage in negotiations with Vince McMahon. His WWE contract ends next April after WrestleMania 34, giving him plenty of time to re-start testing or even claim a desire to do so. He doesn’t have to be an active fighter the day his WWE contract ends.

But, he is a 40 year old who would be looking to follow a five year layoff with probably a two year break in between fights. And he still has the remainder of a USADA suspension to serve as a result of multiple positive tests from his bout with Mark Hunt last Summer at UFC 200.

While there’s no doubt his drawing power would make him very attractive to UFC, if he doesn’t look serious soon, he may give McMahon a reason to discount his options.

One thing is for sure. Just from the reports we’ve seen on Lesnar today, the months between now and his current WWE contract expiring are going to be very interesting.