Just hours before the event is slated to begin, UFC 234: Whittaker vs Gastelum has taken the biggest hit possible. Middleweight champion Robert Whittaker, who was scheduled to fight Kelvin Gastelum in the main event, has been ruled out of tonight’s bout.

Sources close to Whittaker say he was dealing with a pain in his abdomen late last night. ESPN reports the champion was checked into a local hospital at around 2 a.m. and was diagnosed with a hernia. He will require surgery.

This comes as a huge loss for the champion as it is the second year in a row in which he is unable to defend his title in his home country. Whittaker was slated to fight Luke Rockhold in Perth, Australia last February but was ruled out with an injury.

President Dana White confirmed a non-title bout between undefeated middleweight Israel Adesanya and Anderson Silva will now headline the event. Both middleweights were scheduled to meet in the co-main event slot. The bout will remain 3 rounds. The featured prelim bout between lightweights Lando Vannata and Marcos Mariano has been bumped up to the co-main event slot.

The UFC has offered ticket holders a full refund in light of Whittaker’s removal from the main event.

UFC 234: Adesanya vs Silva kicks off tonight at 7pm Pacific time only on Pay-Per-View.