The Canadian Press

The UFC has added a co-main event fight between welterweights Josh Koscheck and Anthony (Rumble) Johnson to UFC 106 on Nov. 21 in Las Vegas.

The UFC was forced to move the previous co-main event between former light-heavyweight champions Tito (The Huntington Beach Bad Boy) Ortiz and Forrest Griffin up to the headline bout after Brock Lesnar withdrew this week citing illness. Lesnar had been slated to defend his heavyweight title against unbeaten challenger Shane Carwin. That fight has been pushed back to early 2010.

Johnson (8-2) is fighting on short notice after knocking out Yoshiyuki Yoshida at UFC 104 last Saturday in Los Angeles. The good news is he didn't work up much of a sweat in the 21 seconds it took to dispatch Yoshida.

The six-foot-two welterweight has good power but has had trouble making weight and tipped the scales in L.A. at 176 pounds, five over the limit.

"Koscheck versus Johnson is a great fight and I give credit to both guys for stepping up and making a fight like this happen," UFC president Dana White said in a statement. "The amazing thing about this fight is that both Koscheck and Johnson are world-class wrestlers, but they can also knock you out with one punch."

Koscheck (14-4) also knocked out Yoshida, in December.

UFC 106 marks Ortiz's return to the UFC after an acrimonious departure some 18 months ago when his contract expired.

He won a narrow decision over Griffin at UFC 59 in April 2006.