UFC heavyweight champion Brock Lesnar has bowed out of his upcoming title defense against number one contender Shane Carwin, citing a flu as the culprit. Lesnar stated that he’s been unable to train for three weeks, which would certainly severely hurt his training camp time. Here’s a quote from UFC president Dana White, via Yahoo!Sports:

He said he’s never been this sick in his life,” White said. “He said it’s been going on for a long time and he just hasn’t been able to shake it.” White said he does not know if Lesnar had the H1N1 virus, commonly known as swine flu.

UFC 106 had initial problems when Mark Coleman pulled out of a scheduled bout with Tito Ortiz, but the UFC managed to get a suitable replacement in Forrest Griffin. There’s no word on whether Carwin will still fight on the card or who a potential opponent could be. The MMA News will keep you up to date on any developments in this story.