The illness that forced Brock Lesnar to pull out of his scheduled UFC 106 championship defense against Shane Carwin still has not abated, and the heavyweight champion will be forced to postpone the bout yet again if he can't begin training at full strength in the next two weeks.

Kevin Iole reported the news at Yahoo! this afternoon. has confirmed with sources close to Minnesota Martial Arts Academy that Lesnar has spent very little time in the gym over the past month. Known for his full-time work ethic in the gym, Lesnar has tried to push through his illness on several occasions over the past week, but grew incredibly fatigued each time and was unable to continue.

Rumors circulated that Lesnar was suffering from the H1N1 virus last week, but that's not the case. In fact, Lesnar doesn't appear to have the flu at all. Blood work done last week to determine the cause of the illness have not been disclosed by Lesnar or his camp, but the camp says it's not the flu.

I'm not a doctor, but I was a medic in the United States Army. Judging from my experience in dealing with soldiers, it would appear to me that Lesnar is suffering from something along the lines of mononucleosis. Lesnar's trainer/coach Greg Nelson voices the same suspicion in Iole's report.

A video showing Lesnar at a recent Minnesota Vikings game circulated through MMA message boards after the postponement announcements was made by UFC president Dana White. The video, showing an apparently healthy Lesnar on the sidelines of a Vikings game and filmed during the time Lesnar was allegedly sick, caused conspiracy theorists around the web to claim that Lesnar pulled out of the fight due to fear of his opponent.

And while Carwin certainly presents a stiff challenge to Lesnar's reign, his camp says that's simply not the case. Lesnar's illness doesn't really affect his day-to-day activities, and he's able to function as he normally does for most of the day.

His training sessions are different, however. Our source confirms Iole's report that Lesnar is unable to push anywhere close to his typical pace during training sessions. He tires quickly and expends energy at a much more rapid pace than normal. Despite public comments, Lesnar is taking Carwin's boxing skills and punching power very seriously and does not want to risk going through a short two-week training camp for the fight.

Lesnar is expected to make a decision regarding UFC 108 by the end of next week. If he's not able to begin training at or near full speed, the bout will be postponed until UFC 109 in February. That will leave UFC 108, the UFC's traditional year-end show, without a championship fight on the card unless the company decides to put together an interim heavyweight championship bout between Cain Velasquez and Antonio Rodrigo Nogueira.

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