UFC light heavyweight champion Jiri Prochazka has suffered a significant injury to his right shoulder, forcing him to not only pull out of his UFC 282 title defense versus Glover Teixeira, but also to vacate his belt. Teixeira declined an opportunity to fight someone else for the title, so the UFC has made former champion Jan Blachowicz versus Magomed Ankalaev the the main event on Dec. 10 at T-Mobile Arena in Las Vegas.

Tim Simpson, Prochazka's manager, said "the shoulder got wrecked in a standard wrestling accident type of thing." UFC president Dana White said the doctors told him that the injury is extensive.

"This is the worst shoulder injury the doctors have seen in UFC history," White told Yahoo Sports. "It's really f***ing bad. His shoulder is very, very bad. He's going to have serious surgery that will require extensive rehab."

Simpson said the injury occurred at the UFC Performance Institute. He said it popped out and someone popped it back in.

"You know how shoulders are, right?" Simpson said. "It pops out and a lot of the time, you pop it right back in. There was a wait and it popped out. And you never really know with a shoulder until you dig into it."

Simpson said the team was in the process of determining when and where the surgery would take place.

Prochazka later released a statement via Instagram in which he says his injury will require surgery and he'll be out for at least six months. The now former champion also said he vacated the belt to not hold up the division, but will fight whoever is champion when he returns.

Prochazka won the title from Teixeira at UFC 275 on June 11 in Singapore. He submitted Teixeira with a rear naked choke with 28 seconds left in a match that is a front-runner for Fight of the Year.

The UFC offered Teixeira a bout against Ankalaev for the vacant title, but he declined it. Yahoo Sports was unable to reach Teixeira, but Hunter Campbell, the UFC's chief business officer, said Teixeira "probably" wanted to win the title back from Prochazka.

"We met with Jiri last night and listen, this guy is one of the classiest humans of all-time," White said. "He is such a warrior and was so bummed out. He brought up stepping aside to us before we ever got there. He's going to be out a long time and at some point, we would probably have had to strip him. But he brought it up to us and said out of respect for the other fighters, he didn't want to hold up the division. Let me tell you, that kid's a stud, man, to react like that.

"We offered Glover the fight [against Ankalaev]. For some reason, he didn't want the fight, so we had to move on. If we couldn't have the rematch, getting Ankalaev, who has the second-longest winning streak in light heavyweight history, and Blachowicz, who is the former champion, is really fortunate. It all fell into place for us as it often seems to do. But that's a great fight, too, and now it's for the full title."

Blachowicz is ranked No. 2 and Ankalaev No. 3 in the UFC's current light heavyweight rankings. Ankalaev is 18-1 overall and has won nine in a row in the UFC since his only career defeat, a triangle choke submission loss to Paul Craig on March 17, 2018, in London in his UFC debut.

Blachowicz is the former UFC champion who lost his belt to Teixeira in Abu Dhabi, United Arab Emirates, at UFC 267 on Oct. 30, 2021. He returned to win one fight, defeating Aleksandar Rakic via TKO on May 14 in Las Vegas. Rakic suffered a knee injury which forced the end of that bout.

The new co-main event at UFC 282 is a lightweight fight between rising prospect Paddy Pimblett (19-3) and Jared Gordon (19-5).