Demetrious Johnson's attempt at a ninth defense of his UFC flyweight championship will have to wait.
Johnson, 29, has reportedly withdrawn from his UFC 201 bout on July 30 in Atlanta because of an undisclosed injury suffered in training camp.
Multiple media outlets have confirmed the initial report from Brazilian site Combate on Friday.
Fighting out of Parkland, Washington, Johnson (24-2-1) was expected to face Brazilian Wilson Reis (20-6) in the co-main event of a card headlined by welterweight champion Robbie Lawler's title defense against Tyron Woodley.
The UFC has yet to announce whether the fight will be postponed to a later date.
The only 125-pound champion in UFC history, Johnson is three months removed from a dominant victory over Olympic gold medalist Henry Cejudo at UFC 197.
Nicknamed "Mighty Mouse," Johnson won the inaugural UFC flyweight title in 2012 and followed up with eight title defenses, lifting him to the top spot in ESPN.com's pound-for-pound rankings.
Reis, 31, is 4-2 since making his UFC debut in 2013. He last fought in January when he outpointed Dustin Ortiz.