Perhaps no other athletic enterprise has undergone such a drastic evolution in their business practices than pro wrestling. It used to be that if you wanted to get into it, you couldn't. Some veterans' stories of how they got into the business sound akin to joining the Illuminati, where mysterious figures would just appear out of the shadows of local gyms, beckoning muscled meatheads into the secretive world of wrestling.

Nowadays, with the carnival tricks of wrestling mostly understood, gaining entry into the sport has become mostly normalized, with its process resembling that of other professional sports. The Undertaker shed light on WWE's more modern approach to recruiting new talent on "Six Feet Under."

"There is a quota of guys they take from independents, but I'm pretty sure the objective now is to hit these NFL Combines, the Big 12 Combines, and get those type athletes," The Undertaker said. "And they do have open workouts, too, they had one in Australia when we were over there a month or so ago [for Elimination Chamber: Perth]. It's a lot different. It's another layer of the evolution of the product and the athletes."

"The Deadman" said that the advantage of scouting talent at NFL Combines is that WWE can find some next-level athletes who may be missing a key element required for NFL success but would not necessarily disqualify them for wrestling success.

"Holy crap. That Big 12 combine I went to, man ... when I played high school, we didn't have running backs, wide receivers running 4.5 [second] 40 [yard dashes] and these guys are 300-pound, 6-foot-6, just motoring," he said.

Last spring, WWE's Performance Center welcomed a slew of athletes from other sports, which included a former college basketball player, a former track and field star, and an undrafted free agent from the Los Angeles Rams.