Tonight's UFC 213 pay-per-view from the T-Mobile Arena in Las Vegas, Nevada was supposed to be headlined by a rematch between current UFC women's bantamweight champion Amanda Nunes (14-4) and challenger Valentina Shevchenko (14-2).

The two ladies fought once before with the fight going to a decision and Nunes earning the win, although not everyone saw it that way. Yesterday Nunes weighed in, as did Shevchenko, and both competitors made weight for tonight's headliner. Reports then surfaced today that Nunes fell ill and had checked into an area hospital for a checkup.

Nunes won the title at UFC 200 in July 2016 with a submission win over then-champion Miesha Tate. She later defended the title against former champion Ronda Rousey, retaining the title with a 48-second technical knockout.

Sick or not?

According to UFC President Dana White, Nunes was cleared by doctors to compete, but it was Nunes and her team who made the final call not to compete tonight. No official word as to why Nunes felt ill has been released, but she did not look to be in the best shape yesterday at weigh-ins despite making the 135-pound weight limit.

"The doctor did a full evaluation and she was medically cleared to fight," White said. As a result of the fight cancellation, the co-main event of Robert Whittaker vs.

Yoel Romero for the UFC interim middleweight title was promoted to the night's main event.

Despite being medically cleared, the UFC organization cannot make a fighter compete if they do not want to. The Nevada Athletic Commission would have called it off once they checked on Nunes and asked her if she felt well enough to compete.

Athletic commissions are put into place to protect athletes and look after the safety of fighters. Fans who bought tickets to the event tonight in Las Vegas were offered an opportunity to have their money fully refunded before they entered the arena.

Book it for September?

The UFC President is hopeful that the rematch will take place September 9 at Rogers Place in Edmonton, Alberta, Canada.

Shevchenko was visibly upset about the fight's cancellation and said, "I feel frustrated about what happened but I won’t relax, will not put down energy in my preparation, and will wait until the UFC gives us another date for the fight."

Thus far the main event for UFC 215 is former UFC heavyweight champion Junior Dos Santos going up against rising heavyweight challenger Francis Ngannou.