UFC 230 is set for Nov. 3 at Madison Square Garden, but the card does not have a main event scheduled.
With nothing settled, two fighters announced they were batting for the 165-pound crown.
The problem is, currently there is no 165-pound title, and the UFC says they know nothing about it.
Nate Diaz and Dustin Poirier made announcements on Twitter within minutes of each other on Tuesday night, all but saying the fight is confirmed.
Though Diaz and Poirier will fight at UFC 230, the bout is scheduled at 155 pounds.
UFC President Dana White denied any knowledge of the weight-class change, telling ESPN.com there is "absolutely no truth" to the rumors.