http://sports.yahoo.com/mma/news;_yl...yhoo&type=lgns Ultimate Fighting Championship heavyweight title-holder Brock Lesnar has mononucleosis and can’t train for at least a month, and perhaps as long as six weeks, UFC president Dana White said Wednesday. Lesnar was forced to pull out of his title defense against Shane Carwin on Oct. 26, a match slated for UFC 106 on Nov. 21 in Las Vegas, because he was unable to train. At the time, speculation was that Lesnar may have had either flu or a case of H1N1, which is commonly known as swine flu. White had targeted the rescheduled bout for Jan. 2 in Las Vegas as the main event of UFC 108, but that is now also out of the question. Lesnar won’t be able to begin training until sometime in December. White said he is unsure when the Lesnar-Carwin fight will occur or whether Carwin will fight an opponent in the interim. “We’re still trying to figure it out and I’m really not sure where any of it stands right now,” White said.