When Brian Foster finally meets World Series of Fighting lightweight champion Justin Gaethje at WSOF 29, he knows exactly what type of challenge he is facing. Gaethje may not be a household name, but he remains one of the most talented lightweights outside of the UFC ranks, an undefeated tank of a man who lives by the gospel of forward pressure and ultra-aggression. Gaethje fights are exciting simply because the 27-year-old thrives within chaos like few in this sport.

But that type of style comes with a cost.

Gaethje has never been much of a defensive fighter, however things reached a different level in 2015, when the Arizona native waged back-to-back wars of attrition against Luis Palomino -- and ate seemingly five years worth of strikes in the process. Now, with Gaethje's fourth title defense set for Saturday night, Foster can't help but wonder how, and when, all of that damage is going to start affecting a fighter who should otherwise be entering his physical prime.

"I've heard it from the higher-ups, the only reason they (other promotions) haven't reached out to snag him is because of that fact," Foster said. "I'd rather not [elaborate] on that, but I've heard from some of the higher-ups that's the reason why they haven't reached out and snagged his ass, because he takes too much damage. He flirts with disaster out there. You flirt with brain damage.

"I've been down that path and have received nowhere near the damage that young man has received, only because I don't put myself in that position. Yes, stepping forward is very scary. But stepping forward, stepping into that damage, taking that damage to inflict it, in my mind, shows one dimension."

The criticism is one that Gaethje has heard before, and though the WSOF lightweight champion remains thoroughly unapologetic about his style, Foster can understand Gaethje's defiance because it is a style that has yet to fail.

Gaethje is a perfect 15-0 in his career. Seven of Gaethje's eight WSOF appearances have ended with his opponent battered and bloodied on the canvas. Yet Foster, who earned his title shot with an inspiring run through WSOF's recent lightweight tournament, sees in Gaethje an opponent who has begun to stagnate with his growth as a fighter.

"What gather from it is that he's having a hard time evolving," Foster said. "You have to change it up. You have to keep guys guessing. And as far as I'm concerned, he hasn't done that. He hasn't surprised me one bit.

"This isn't just barbaric and brawling. You have to be smart. The smarter fighter, the majority of the time, prevails. The more prepared fighter usually prevails, and I've shown time and time again that I'm not going to give up. It doesn't matter if I go in and get my ass whooped by Justin, he ain't going to make me quit. He ain't going to retire me. And he damn sure ain't going to knock me out. He's daydreaming. If you can show me on my résumé where that's happened to me, then there's a chance. But it's not. You beat a couple f**king old-school UFC vets and you think that's special? No, you beat an out-of-shape Melvin Guillard. You fought Nick Newell, who has one hand, and you fought (Rich) Patishnock coming in on two weeks short notice for the title in the first place."

With a career that spans back a decade, Foster has been around this game long enough to understand the benefit adversity can have on an athlete's long-term prospects. In 2011, his five-fight UFC run came to a tragic end with a submission over current top-10 welterweight Matt Brown, followed by a pre-fight physical that appeared to show signs of a brain hemorrhage. Foster spent much of the next four years desperately trying -- and ultimately succeeding -- to prove the test result was a mistake.

The experience taught him a lot, but most of all it led him to grow much as a fighter and a person. So when Foster sees the ‘0' on the right side of Gaethje's record, he knows he is looking at an athlete who has yet to taste that adversity, adjust, and strive through it to reach his peak.



"There's a reason who Conor (McGregor) is who he is right now," Foster said. "You know why? Because he lost and he f**king hated it. He didn't like that feeling. Justin has lost before in his collegiate career, but he's never lost in a fight. So, in my opinion, I feel like the best Justin Gaethje is yet to come. Once he feels defeat and makes that decision to not give up, and to learn and continue to grow, I think that's when you'll see the best Justin Gaethje you've ever seen."

Whether those adjustments will come after WSOF 29, Foster is unable to say. But either way, Foster hopes this isn't the last time the two lightweights meet inside the WSOF cage.

"What's Floyd (Mayweather), 40? Something like that," he said. "But there's a reason he's able to compete past all the fights he's been in, because he does not take damage. The rate that Justin is going, leading with his forehead and just stepping forward, yeah dude, you're looking at 31-32 years old and you're done. That's just speaking the truth, man. That's coming from a guy who's 31 years old."