The "Natural Born Killer" will still face a fellow top-ranked opponent as Johny Hendricks (14-1, 9-1) has agreed to fill the open slot.
"Once we knew Rory had to withdraw, we started looking for potential replacements," UFC President Dana White said. "Johny Hendricks called me and said he wanted that fight, so we're going to give it to him a shot at Carlos."
UFC 158 will be headlined by Georges St-Pierre, one of the sexiest men in MMA today.
St-Pierre fights Nick Diaz, who is coming off a year-long suspension.
The UFC 158 main card airs on pay-per-view following prelims on FX and Facebook.
UFC 158 is set for March 16 at the Bell Centre in Montreal, Canada.
If St-Pierre knocks off Diaz, there's a chance that his next opponent will be UFC middleweight champ Anderson Silva.
"Anderson would go to (170), too," White said. "Yeah, he said he'd do it. He says he can make (170) easy. It's insane."
Besides St-Pierre, here's a look at the sexiest male MMA fighters in the world today.