White was left frustrated when the Brazilian star pulled out of her bout with Valentina Shevchenko just hours before its scheduled time slot on Saturday, leaving a significant gap at the top of the card.
Nunes claimed she was too unwell to compete in what would have been her second defense of the belt after beating Miesha Tate to secure the title and demolishing Ronda Rousey in December. However, White said that doctors had cleared her to fight after conducting numerous checks.
"It was 90% mental and probably 10% physical," White said. "A lot of fighters have had times they didn’t feel right and we’ve had guys who are outright sick.
"I don’t think I’ve ever had a situation like (this) where she was physically capable of fighting. I won’t do that again. I won’t main event (her) again."
After Nunes pulled out, there was heavy speculation that her struggles to make the 135-pound bantamweight limit had caused her to suffer an illness severe enough to keep her out of the fight.
Shevchenko was furious and said she believed Nunes had tried to gain an advantage by performing a late and drastic weight cut, before immediately bulking up again.
"When you receive notice you can fight, but you don’t want to fight, it’s like, you had three months to prepare," Shevchenko said. "It’s a big, huge event. You can’t just say, 'Oh no, I don’t feel good today.' My goal is to be the champion and I don’t care (against) who, when and where."
The UFC will now try to reschedule the event for UFC 215 in Edmonton on Sept. 9. Shevchenko was paid a discretionary $70,000 to offset her disappointment, while Nunes received nothing.
"We didn’t pay her," White said. "We have never see anything like this from her before. There is no pattern of her refusing to fight somebody.
"She was medically cleared, physically okay. They found nothing wrong with her, but she didn’t feel right. You can’t make anybody fight. Was it the weight cut? No. She might not have been affected by the weight cut, but she was healthy."
Ever since Rousey surrendered her belt to Holly Holm in November 2015, the bantamweight division has been through extraordinary upheaval. Holm was dethroned by Tate in her first defense, who then in turn was trounced by Nunes.
This weekend’s saga was the latest wild development, one which took the sting out of the fight card. Robert Whittaker’s bout against Yoel Romero for the interim middleweight title was bumped into the main event slot, and Whittaker emerged from a tough battle with a unanimous points victory.
In truth, however, this was one of the UFC’s more forgettable nights and one that White will be keen to put in the rear-view mirror.
Follow Martin Rogers on Twitter @mrogersUSAT.