As well, former WWE superstar CM Punk makes his first octagon appearance in nearly two years as he takes on fellow welterweight Mike Jackson as a plus-175 underdog, while Holly Holm vies for a second win in six fights as she takes on Megan Anderson as a minus-225 favourite in a clash of women's featherweights.
So, for the second consecutive fight, Romero will be in a planned championship bout without the opportunity to claim the title.
UFC officials had told Sporting News that it is unknown whether the bout will still happen.
"This fight, as far as I'm concerned, I have 25 minutes to try to finish him - and I'm going to use every single second of those minutes to try to achieve that".
Romero was the last of the 26 fighters on the card to hit the scales in Chicago, where the UFC 225 event will take place on Sunday.
Whittaker said his family helped him get through the rough 11 months.
"I don't think he can change that drastically at his age and in this little amount of time before the fight", he said. You may also be able to stream part of the event on the FOX Sports GO app. The Cuban missed weight, so the fight will be a non-title event.
The "Soldier of God" initially weighed in at 186 pounds and was given two hours by the Illinois State Athletic Commission to lose one pound. He was scheduled to fight for the UFC Middleweight title on Saturday against Robert Whittaker.