Dana White wants to book a fight between Khabib Nurmagomedov and Justin Gaethje "as soon as possible" and was caught off guard by the timing of Henry Cejudo's retirement announcement.
Gaethje massively upset the odds to defeat Tony Ferguson at UFC 249 in Jacksonville on Saturday to win the interim lightweight belt.
UFC made its comeback behind closed doors amid the coronavirus pandemic and in a brutal main event Gaethje stopped his opponent in the final round, with Ferguson having absorbed plenty of punishment.
After the fight, Gaethje called out Khabib, who was originally slated to face Ferguson, and the lightweight champion later hinted on social media he was ready for the bout.
Speaking about that possibility, UFC president White said: "Khabib tweeted that he's ready to go this summer.
"So, we will get back home next week and figure out what's next and get this fight together as soon as possible."
On the main event, White pondered whether Ferguson having to cut weight twice in the space of a month played a part in an off night for the veteran but paid tribute to his heart.
"As a promoter, you can't go out and guarantee people are going to see anything. In my 20 years of doing this, it is maybe only the second time I've guaranteed you that the main event would be incredible," he added.
"The fight was really good. I don't want to take anything away from Gaethje – he fought an incredible fight – but I thought Tony looked off, looked slow. I would have to imagine that cutting weight twice in a month will affect you. I don't if that was it or what.
"But the guy [Ferguson] isn't human. Nobody takes Gaethje's punches like that – nobody I've seen since I've been watching him fight.
"Tony Ferguson is a special human being. Tony took a lot of damage tonight. He usually knocks people unconscious with some of those shots."
Gaethje's win was not the only shock of the night. Cejudo defended his bantamweight belt with a contentious second-round TKO victory over returning great Dominick Cruz before announcing he was retiring.
White said Cejudo had been considering the idea but did not know it was coming this soon.
"He's been talking about retirement with us for the past several months. I didn't know he was going to do it tonight, but he's been talking about it," White said.
"If you start talking about retirement in this business, it's probably a good idea.
"Although, I think he's one of the best in the world and looked incredible. Cruz is a bad-ass fighter with a very high fight IQ and very motivated to win. Tonight was a big win."