White has also confirmed that Whittaker will be heading into surgery today to correct the issue that's forced this sudden change of events.
It means the no less anticipated co-main event between Israel "The Last Stylebender" Adesanya and Brazilian legend Anderson Silva will top proceedings Down Under.
For all the good luck that the UFC had in keeping fights scheduled through January, February is not starting off the same way.
"He was taken to hospital and diagnosed with a hernia", ESPN reporter Brett Okamoto revealed.
ESPN's Ariel Helwani does not paint a pretty picture of what occurred that night, with Whittaker now in surgery.
UFC 234 takes place Saturday at Rod Laver Arena in Melbourne, Australia. Whittaker did compete in June 2018 against the man he defeated for the interim title, Yoel Romero, though that fight was not contested for Whittaker's championship due to Romero significantly missing weight.
Despite being elevated to the main event, Adesanya's bout will remain a three-round fight.
Earlier this week, White had said the winners of the Whittaker-Gastelum and Adesanya-Silva fights would meet later this year.