Just when the situation couldn't get any worse, it did.

When Brock Lesnar pulled out of UFC 106 due to illness, most everyone hoped that he had a severe case of influenza and would recover in time to defend his title against Shane Carwin at UFC 108 on Jan. 2 in Las Vegas.

The UFC even issued Lesnar and Carwin new bout agreements for UFC 108.

Carwin will still get his shot, but the latest news on Lesnar, that he has mononucleosis, will push it back even further, to an uncertain date.

"Guys, my manager, Jason Genet, just told me that UFC 108 is not happening. Brock has mono and what the UFC has told me is that I have earned the title shot, but I have to wait for the titleholder," Carwin wrote in the blog on his official website Wednesday night.

UFC president Dana White later confirmed Lesnar's diagnosis to Yahoo! Sports' Kevin Iole, indicating that the UFC heavyweight champion would be unable to train for the next four to six weeks, effectively scrapping any chance at a Jan. 2 date.

The title bout is still uncertain until Lesnar's health improves.

"Our role now is to wait," Genet told MMAWeekly.com on Wednesday night.

With middleweight champion Anderson Silva and light heavyweight champion Lyoto Machida on injured reserve, lightweight titleholder B.J. Penn booked for UFC 107, and welterweight kingpin Georges St. Pierre just getting back into the swing of training, that leaves UFC 108 with no main event and tickets going on sale in little more than a week.

Earlier on Wednesday, MMAWeekly.com reported that a heavyweight bout between former UFC interim champion Antonio Rodrigo Nogueira and Cane Velasquez was in the works for UFC 108. With this latest update on Lesnar's health, the pressure may increase to make that fight happen.

SI Apps
We've Got Apps Too
Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide - from Peter King, Tom Verducci, Lee Jenkins, Seth Davis, and more - delivered straight to you, along with up-to-the-minute news and live scores.