Yoel Romero to replace middleweight champ Robert Whittaker at UFC 221

Rockhold (16-3) will now face Yoel Romero (12-2) for an interim 185-pound championship.

Many thought that, following roughly a year-and-a-half of uncertainty during Bisping's chaotic reign, the division was finally set for some clarity and progression towards the norm with the champion facing a rightful number one contender, and indeed the decision to have Whittaker headline UFC 221 was an obvious one considering his ties to Australia.

An injury has shaken up the UFC 221 card next month, as Robert Whittaker is out, and Yoel Romero in.

UFC 221 takes place February 11 at the Perth Arena in Western Australia. The bout will now be for the interim middleweight championship.

"I've been ruled medically unable to compete and wont be able to defend on home soil". The new main event at UFC 221 will still have championship gold resting in the balance as Rockhold vs. Romero will fight for an interim strap with the victor facing Whittaker in a unification bout later in 2018.

The nature of champ Whittaker's injury was not revealed.

St-Pierre's move allowed Whittaker to exchange his interim title for the undisputed crown, and news of the fight with Rockhold signaled a return to business for a division that had been slowed by chaos for the past year.

While Rockhold vs. Romero is a high-quality replacement for Whittaker vs. Rockhold, it is likely to disappoint fans in Perth and those who had planned to travel from other parts of Australia. Branch will now be looking for a new opponent.

Prior to that loss, Romero had won eight in a row, including six by knockout.

Romero had been scheduled to fight David Branch at UFC On FOX 28 on February 24th in Orlando, Florida, so he was already in training, but he'll now have two weeks less to prepare for a higher stakes fight. That marked his first fight back after being knocked out by Michael Bisping at UFC 199.

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.