Rockhold will remain in the card and in the main event, now facing late replacement Yoel Romero for the vacant UFC Interim Middleweight Championship.
So much for that plan.
Middleweight champion Robert Whittaker has been forced out of the main event due to an undisclosed injury.
He will now face the victor of Romero versus Rockhold in a unification bout, with all customers who purchased tickets for UFC 221 eligible for a refund. The bout will now be contested for the interim UFC middleweight title.
The newly-crowned middleweight champion was supposed to make the first defence of his 185lbs crown at the promotion's second pay-per-view card of the year, which takes place in Australia on February 11. "I've been ruled medically unable to compete and won't be able to defend on home soil". "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 victor of the main event".
Romero, who won an Olympic silver medal in wrestling for Cuba at the 2000 Sydney Games, now gets a chance to claim UFC gold on the other side of the country.
Romero (12-2) hasn't competed since his loss to Whittaker and had been preparing for a February 24 fight against David Branch.
Adam Hill at or.
"I would like to apologize to all my supporters and fans of MMA for not being able to put on the show you deserve", he wrote. He defeated David Branch (21-4 MMA, 1-1 UFC) back in September, and has been calling for another shot at the title since being knocked out by Michael Bisping in 2016. I wish Yoel and Lucas [Rockhold] the best.