UFC 141: Alistair Overeem promises to send Brock Lesnar back to WWE on Dec. 30

This despite persistent rumors that Alistair Overeem won't be fighting Brock Lesnar at UFC 141 on Dec. 30 in Las Vegas, Nevada.

The MMA media was working overtime last night at the UFC 140 post-fight press conference, as Twitter was alight with word that something went wrong and "The Reem" wouldn't be making the trip to the MGM Grand Garden Arena.

When asked about Overeem's status, UFC President Dana White responded with a perturbed look and a question of his own:

"Where do you guys get this sh*t? I also heard Lyoto Machida was sick. If someone is hurt, I usually know these things before you guys."

That's all well and good but the rumor had nothing to do with an injury. In fact, Overeem is on the agenda for the Nevada State Athletic Commission (NSAC) on Monday. That could be just to get his fight license but rumors persist that there's more to it than that, namely that it has something to do with his pre-fight drug test.

One particularly odd rumor circulating is that Overeem left Las Vegas not because he had to care for his mother, who is having complications from cancer, but because he was avoiding taking a drug test.

Again, to be clear, these are just rumors for the time being and we'll know more Monday.

For his part, Overeem is writing in his blog at Yahoo! Sports that he's unaffected by his trip back to Holland and he still has plans on sending Lesnar right back to where he came from:

But to my fans who are worried that I will not be 100 percent ready to rip Brock Lesnar apart on December 30 at the MGM Grand in Las Vegas, let me promise you: coming back to Holland for this camp will not be a factor at all. ... I say to MMA fans, again, don't worry, I will be sending this guy back to WWE for you.

Bold claims from "Demolition Man," who will be making his UFC debut after spending most of his career fighting overseas. Pride, Strikeforce, K-1; he's done it all. Everything except compete inside the Octagon.

That's why his bout against Lesnar is so highly anticipated, other than the obvious reasons.

And that's also why the rumors are so troubling. If true, not only would they affect his match-up against Brock later this month, they would likely affect his fighting career with the UFC.

He made sure to reiterate in his blog exactly why he went home:

My mom is doing ok. She's had cancer twice in the past, a very aggressive kind and it was a long ordeal for her and my family. The treatment she had was very hard; she had experimental treatment to burn the tumor from the inside out. It worked and saved her life, but there were complications from it. Recently, she had a check-up and the doctors found a couple of cells in her body that they were concerned about. That's why I flew home.

That's coming from the man himself, as opposed to the rumors swirling on Twitter. That doesn't mean there isn't something to them, though, and we'll keep you updated on Overeem's status in the coming days.