by Ken Pishna – MMAWeekly.com
With a win over Ben Rothwell at UFC 104 on Saturday night, Cain Velasquez appeared poised for a shot at the winner of the heavyweight title bout at UFC 106 between champion Brock Lesnar and challenger Shane Carwin. Velasquez may maintain that position, but if so, he’s going to have to wait awhile.

UFC president Dana White on Monday told Yahoo! Sports and later confirmed to MMAWeekly.com that Brock Lesnar had to withdraw from the Nov. 21 title defense due to extreme illness. Apparently, the massive UFC heavyweight champion has been ill for “more than three-and-a-half weeks,” leaving him unable to train.

It came down to the make or break point with the fight just one month away.

White told MMAWeekly.com that he was unsure if the illness was the widely feared H1N1 virus that everyone is worrying about this flu season, saying, “I’m no doctor.”

He said that he was made aware of Lesnar’s situation Monday morning.

“We’re not sure what we’re gonna do,” he told MMAWeekly.com reporter Steven Marrocco at The Ultimate Fighter tryouts in Los Angeles.

With all of the promotions other champions already scheduled, having just fought, or healing up from injuries; the promotion later in the day announced via UFC.com that a rematch between Tito Ortiz and Forrest Griffin, originally the UFC 106 co-main event, would be slotted up to headline status.

Ortiz won their initial meeting, at UFC 59 in April of 2006, via split decision.

After speaking with his management, Carwin posted on his official Twitter account, “Looks like it is postponed till Jan. 2,” indicating that he and Lesnar could meet at UFC 108 in Las Vegas.

(UPDATED / 2:20 p.m. PST, Oct. 26 – UFC announced Tito Ortiz vs. Forrest Griffin for UFC 106 main event.)

(UPDATED / 2:00 p.m. PST, Oct. 26 – With information from Carwin on new date for bout with Lesnar.)