Injuries are a part of the fight business, and especially when it’s a bout of significance, a serious injury can threaten an entire card. In boxing, the entire card is built around the main event when it’s a pay-per-view show.

So, if Canelo Alvarez received a massive, crescent-shaped cut above his right eye 12 days before a fight the way the UFC’s Charles Oliveira did late Monday, there would be no doubt: The entire card would be off.

Somehow, though, UFC 294 not only has survived the loss of Oliveira, the former lightweight champion who was forced out of his Oct. 21 bout in Abu Dhabi against champion Islam Makhachev, the fight has somehow gotten even better.

Featherweight champion Alexander Volkanovski agreed to step in with 11 days' notice and face Makhachev in the main event of UFC 294, a rematch of a phenomenal bout at UFC 284 that Makhachev won by the slimmest of margins.

“It took one phone call,” UFC president Dana White said of getting Volkanovski onboard.

Despite the loss on the record, so many thought Volkanovski won the fight that he remains ranked ahead of Makhachev on the UFC’s pound-for-pound rankings. Volkanovski is No. 2 behind heavyweight champion Jon Jones, with Makhachev at No. 3. Oliveira is No. 5.

The UFC is the most successful MMA promotion in the world because it’s put together the best business operation and because it knows how to, as White calls it, set up all the bells and whistles to make a fight enticing.

But don’t let that distract from the obvious point here: What these fighters do on a nightly basis is incredible, and specifically what both Volkanovski and Makhachev are doing in accepting a bout of this magnitude is exceedingly rare on such short notice in most combat sports.

By each saying yes — Makhachev agreeing to defend against Volkanovski and Volkanovski agreeing to fight on less than two weeks' notice — it quite literally saved the show.

Makhachev woke up at 5 a.m. Tuesday for his morning prayer to a message from his manager, Ali Abdelaziz, telling him Oliveira was out. With sleep still in his eyes, Makhachev never hesitated.

“He said, ‘Your opponent is out. They’re looking for someone new,’” Makhachev told Yahoo Sports on Wednesday. “I sent him a message and I said, ‘Just find someone who can make 155 [pounds], that’s it.”

He didn’t care if it was Volkanovski, or Mateusz Gamrot or any other top contender. He was determined to defend his belt and show he’s the best lightweight in the world.

“I’ve been training for the last three months, very hard, so very hard,” Makhachev said. “Who cares who is going to be there? If Jon Jones can make 155, let’s go.”

When White confirmed a week or so ago that Gamrot would serve as the back-up for this fight, it made him the obvious replacement for a situation like this. That’s the point of the back-up. Yes, it would have been saved had Gamrot gotten the fight, but the card would have been sapped of a lot of energy. Oliveira lost his title to Makhachev and was granted an opportunity to regain it. With all due respect to Gamrot, there was no cachet at this moment with a fight between he and Makhachev.

Yes, Sean Strickland proved at UFC 293 that even a significant underdog can win a championship. Such is the quality of the matchmaking in this promotion. The work of matchmakers Sean Shelby and Mick Maynard is consistently exemplary, and they along with White and Hunter Campbell, the UFC’s chief business officer, consistently hit it out of the park on the fights they put together.

The fighters, though, are the ones who saved it by taking extraordinary risks. If Makhachev has a great performance and cleanly defeats Volkanovski, he won’t get as much credit as he deserves. His win will be diminished by the fact that Volkanovski basically didn’t have a camp. At a point before the fight when the fighters are close to starting their taper, Volkanovski has to step it up to prepare for Makhachev specifically.

Yet each said yes, without hesitation.

“You know, what does this title represent?” Makhachev asked rhetorically. “It means you’re the best in the world. And if you are the best in the world, it doesn’t matter who is going to be there across from you. What could I say? No? Never. Let’s do it.”

That attitude trickles throughout the UFC’s 700-plus fighter roster and throughout the sport.

It might have been best to wait, to cancel or at least delay the fight, but that would have been the easy way out. Neither Islam Makhachev nor Alex Volkanovski look for the easy way out.

It’s a large reason why they are best in class, and also why this still-growing, still-developing sport is so amazing.