Roy Nelson has proven time after time that he can take a licking and keep on ticking.

Case in point, in his bouts against Fabricio Werdum, Junior dos Santos and Stipe Miocic, "Big Country" was tagged repeatedly by the heavy-handed Heavyweights hitters for three rounds. And while he came up short against all three men on the judges' scorecards, Nelson never wavered, refusing to go down despite the abuse.

Furthermore, the pot-belly pugilist has only been knocked out once in his mixed martial arts (MMA) career, which came at the hands of former Ultimate Fighting Championship (UFC) 265-pound champion Andrei Arlovski back in 2008 under the Elite XC banner.

Even though Nelson's chin is proven, Daniel Cormier believes it will eventually "expire" thanks to all the punishment it has absorbed over the years.

And don't be surprised if the "expiration date" happens to be Oct. 19, 2013, the night "DC" and Nelson tangle in Houston, Texas, during the UFC 166 co-main event.

Cormier breaks it down (via ESPN):

"Every person, every tough guy you've ever seen fight, whether it's in boxing or martial arts who is known for having a great chin -- there's an expiration date on that. There's a number these guys can take. What if the last one from Stipe Miocic was the one that was one too many? Maybe the expiration date on Roy's chin was up in Canada. Maybe mine are the ones he can't take."

While Cormier's bread-and-butter is clearly his wrestling, the former Olympian does indeed posses the hands to get the job done on the feet, a skill he proved by knocking out Antonio Silva in round one back in 2011.

Nevertheless, going toe-to-toe against a dangerous striker such as Nelson isn't the wisest gameplan, especially for a fighter looking to keep his perfect MMA record intact. Then again, "DC" has never been one to back down from a fight and is looking for an "impressive" victory in "H-Town" to justify his asking for a title shot once he makes the drop down to Light Heavyweight division.

A knockout victory over "Big Country" could be just what he needs. But, as history has shown us, that is no easy task to accomplish ... to date.