Jon Jones is understood to have failed a drug test ahead of UFC 200, elevating Mark Hunt and Brock Lesnar to main event status.
The Nevada State Athletic Commission reportedly notified the UFC of Jones' failed drug test. The substance he tested positive for was not disclosed.
Jones, the interim light heavyweight champion, was immediately withdrawn from UFC 200 with no substitute named to fight Cormier.
“This sucks, I don't know what to say,” UFC President Dana White said.
“It sucks. It's unfortunate.
“These type of things are going to happen. It could have been a lot worse. Jones might get two years for this.”