Robert Whittaker out of UFC 234 main event vs. Kelvin Gastelum

Just hours out from the card, UFC 234 has lost its main event.

Robert Whittaker is out of his middleweight title defense against Kelvin Gastelum due to a hernia in his abdomen, ESPN’s Brett Okamoto reported Saturday afternoon.

Whittaker was sent to the hospital early Saturday morning (late Saturday night local time in Melbourne, Australia) after complaining about a pain. There, he was diagnosed with the hernia.

According to Okamoto, Whittaker is scheduled to undergo surgery on Saturday for the hernia.

With the cancellation, a middleweight bout between Anderson Silva and Israel Adesanya is the new UFC 234 headliner. Before Whittaker vs. Gastelum was off, Silva vs. Adesanya was expected to determine the No. 1 contender at 185 pounds.

Whittaker is coming off a non-title win over Yoel Romero in a rematch, which many consider 2018’s “Fight of the Year.” Whittaker was expected to make his first title defense in that fight, but Romero missed weight for it.

Whittaker won the interim title in his first fight with Romero in July 2017, and was promoted to undisputed champion later that year after Georges St-Pierre vacated the belt.

Gastelum is coming off a win over Ronaldo Souza last year. He has won two in a row.

UFC 234 takes place Saturday night at Rod Laver Arena in Melbourne, Australia. Lando Vannata vs. Marcos Rosa has been promoted to co-main event from the early preliminary card.