Australia's Robert Whittaker has faced a significant setback just before his highly anticipated showdown in Saudi Arabia against Khamzat Chimaev.

The reason behind his cryptic post 'Anyone, Anywhere, Anytime' has also been revealed.

UFC officials confirmed this morning that Chimaev is out of the June 23 main event in Riyadh and will be replaced by Ikram Aliskerov.

Aliskerov, a Dagestani fighter, is on a winning streak of seven consecutive victories, including his first two since joining the UFC from the 2022 season of Dana White's Contender Series.

Initially, the popular Sydney fighter believed that a win over the unbeaten Chimaev would position him as the next contender for the UFC middleweight title, currently held by South Africa's Dricus du Plessis.

According to Fox Sports Australia, a championship bout between DDP and New Zealand's Israel Adesanya is being discussed for UFC 305, scheduled to be held in Perth on August 18.

However, former champion Sean Strickland has also indicated that he is now willing to wait for his next fight to be against the winner of that bout after recently defeating Costa at UFC 302.

Strickland took the title from Adesanya in a major upset at UFC 293 in Sydney, Australia, last September.

Dana White said in a video uploaded to social media that Chimaev is 'violently ill' and has returned home to recover.

The announcement came just hours after Bobby Knuckles posted a highlights video on social media with the phrase, 'Anyone, Anywhere, Anytime.

' This withdrawal adds to a tough month for UFC fans, with rumors that Irish megastar Conor McGregor may also have to withdraw from his highly anticipated UFC 303 main event against Michael Chandler on June 30.

Chimaev's withdrawal continues a series of inactivity issues for the undefeated star, which also includes injuries and a severe case of COVID-19.

While he remains undefeated in his two fights since moving up to the UFC middleweight division, Chimaev hasn't fought since his win over former UFC welterweight champion Kamaru Usman at UFC 294—a short-notice booking after his original opponent, Brazilian Paulo Costa, withdrew just days before the fight.

Meanwhile, Whittaker defeated Costa at UFC 298 earlier this year.

Before that, he lost by TKO to current UFC middleweight titleholder Dricus du Plessis at UFC 290.