Robert Whittaker’s coronation as UFC middleweight champion in his home country will have to wait. 

Whittaker, the newly-crowned UFC middleweight champion following Georges St-Pierre’s decision to relinquish the title he won from Michael Bisping at UFC 217 last November, has been forced to pull out of the headline bout, citing an undisclosed injury. The featured attraction will now have Luke Rockhold, Whittaker’s original opponent, facing off with Yoel Romero in the latest interim title bout arranged by UFC officials.

ESPN first reported the news and was later confirmed by the UFC’s social media team.

“I’m beyond disappointed that I’m unable to defend the title in my home country of Australia,” Whittaker said in a statement. “I hope the fans enjoy what should be a great night of fights at UFC 221 and I look forward to a recovery as soon as possible that will have me back in the Octagon to face the winner of the main event.”

I would like to apologize to all my supporters and fans of MMA for not being able to put on the show you deserve. I’ve been ruled medically unable to compete and wont be able to defend on home soil. This card meant so much to me and I’m devastated for not being able to fight. All I can do is focus on getting healthy to come back better than ever. All the best to Yoel and Luke for their fight and ill be waiting…

A post shared by Robert Whittaker (@robwhittakermma) on Jan 13, 2018 at 12:34am PST

Whittaker, the winner of eight straight bouts, previously defeated Romero by unanimous decision to claim the 185-pound interim title which was later upgraded to the undisputed title after GSP vacated the belt. Romero had been slated to face David Branch next month, but will now face off with Rockhold in what should be a genuinely intriguing middleweight contest.

Rockhold has fought just once since losing his title to Michael Bisping nearly two years ago; a second round victory against Branch last September.