Nick Diaz failure to show up at consecutive UFC 137 press conferences to promote his bout against Georges St. Pierre on Oct. 29 in Las Vegas cost him the chance to compete against the best in the world for the welterweight championship.

It also opened the door for Carlos Condit to step up to the plate for the opportunity of a lifetime. And he did just that, taking less than 15-minutes to accept the fight.

Not only did Diaz not live up to his contracted duties as a Zuffa employee, he seems to have completely disappeared off the face of the Earth. No one, not even his coach and good friend, Cesar Gracie, can find him.

What would possess Diaz to do such a thing? Why would he throw away the biggest opportunity of his life?

Gracie has a few theories. On top of telling MMAFighting.com that Diaz "acted like a little kid," he believes a "very deep, ingrained social anxiety" is the root cause of all this:

"I would have driven him to Vegas if it came to that. I don't care. He just turned his phone off and acted like a little kid. It just doesn't cut it. Nick is like family to me. We're going to have a long discussion, hopefully with Dana, to see if he's still in the UFC or not. But let's face it, Nick is 28 years old. I talked to Dana about this before, and I think a big problem with all of this is Nick has social anxiety. He doesn't like to go and be away from home. He has no trouble fighting in the cage, though. ... He doesn't feel comfortable being around people. He has a very deep ingrained social anxiety, and it's something he probably needs help for, I think. I think that's why he self-medicates himself with the marijuana. That's my amateur opinion. He did the same crap with Paul Daley and a couple other guys. It was the same Nick Diaz. It's not the pressure of fighting GSP. It's the pressure of doing a news conference before the fight. Fighting is no pressure because he gets to beat someone up or get beat up."

Strong words, made even stronger considering the source is a man who has played such a major part in the growth and progression of Diaz not just as a fighter but as a person.

That said, these issues are nothing new for the troubled Stockton, California native, and all parties involved knew exactly what they were getting into when they agreed on setting up the fight.

Unfortunately, what would have been one of the biggest fights of the year is not to be.

Attention turns now to the status of Diaz and whether or not there's more to the story than meets the eye. At the very least, the hope is that Diaz is okay.

We'll continue to keep you updated as more becomes available.