But the eccentric Minnesota lightweight soon got to know his foe. Green, a veteran Southern California fighter, began trolling Volkmann's Twitter page and getting under his skin.
And that, Volkmann told Ariel Helwani on The MMA Hour, has made their undercard bout at the Mandalay Bay Events Center into something personal.
"He was adding me on Twitter, and he was kind of harassing me a little bit," Volkmann said. I said ‘just leave me alone, you Twitter bully.' I don't remember exactly what he was saying, something about he was going to come in and knock me out. Yeah. It was really annoying, to be honest."
Volkmann, who is 6-1 since dropping to lightweight, has done so without much prior knowledge of his opponents' styles.
"I don't really know most of these guys I fight until I find out [about the fight] and I watch a little video on them," he said. "I haven't fought anyone on the main card so I haven't really watched anybody."
With the opportunity to study up on Green, Volkmann sees what others have found: a wild brawler. Green's most infamous fight came at Affliction 2, when he low blowed Dan Lauzon three times in the first round, only to have Lauzon rally and submit him before the round was out. But Green's also honed his game since then and makes his UFC debut on the heels a four-fight Strikeforce win streak.
"[Green is] throwing crazy punches, chaotic, that's about it," said Volmann. "He's a street fighter. That's about it. It's dangerous, it's very dangerous, I have to time the punches. When I see the weight on the foot I know he's going to be throwing heavy punches. I know to get in and take him down."
Volkmann is coming off the biggest victory of his MMA career, an October win over Shane Roller in Volkmann's home state of Minnesota. His impressive rear-naked choke victory flew in the face of those who consider Volkmann's wrestling-based style boring.
With a win over Green, Volkmann would improve to 7-1 at 155, an accomplishment he feels should put him in the mix.
"Every time I fight, I feel like I'm in a fight for my career," Volkmann said. "I don't know why that is. People on Twitter say if I'm lose, I'm going to get cut. ... You'd think I'd be 7-1 at 155 [he'd be in the mix]. There's no guarantees. Finishes and knockouts are all the UFC wants."
As for Green's Twitter taunts, Volkmann, who has earned his fair share of notoriety through his post-fight interviews, says he's going to save rebuttal until after the fight.
"I'll just save it for the after-fight video," he said. "I'll say when I want for the postfight interview. I have some stuff on my mind. You'll find out."