Jake Shields is known as one of the toughest no-gi exponents in the world, so can you believe people once questioned his legitimacy as a submission grappler?

Shields, who will fight on the upcoming Submission Underground Presented by Chael Sonnon & FloSports on July 17, recounted a story on Nick the Tooth's podcast. 

The MMA fighter and jiu-jitsu black belt says that back in the day people "gave his coach shit" saying Shields wasn't really a purple belt. 

"I've never really trained in the gi that much," said Shields. Training at Cesar Gracie's gym alongside the Diaz brothers and other fighters, he said as everyone was focused on MMA he never really had the opportunity to train in the gi. 

"I did one tournament in the gi. Cesar gave me a purple belt and some Brazilians said 'you're clearly not a purple belt, they were giving Cesar shit. 

"So I had to go do PanAms, I think I put on a gi like three times and then went and smashed everyone at PanAms as a purple. After that no-one said I wasn't a purple belt." 

Gi vs No-Gi

Even with his wrestling and MMA experience, Shields says he doesn't believe there's too much of a divide between gi and no-gi. 

"I don't think they're that different. For me, it's the same sport. Obviously I'm better no-gi, but I can put on a gi and still be good. It just changes the grips a little bit is all." 

Shields' resume as a submission grappler includes two dominant performances over highly-competitive black belts Roberto 'Satoshi' and AJ Agazarm both in the last two years. 

In fact, the MMA fighter's credentials go way back -- he took third in his category at ADCC 2005, known as possibly the toughest no-gi submission grappling event in the world. 

Shields says he'd love to do ADCC again, should the opportunity arise. "It was cool, I liked it. I'd do it again, it was fun." 

Watch Jake Shields in action this weekend over on FloCombat -- FloGrappling annual members get access to watch FloCombat events, plus all the great content from sites like FloWrestling and more, for free. Sign up to watch here

Submission Underground presented by Chael Sonnen and FloSports 

Ronny Markes vs. Vinny Magalhaes 
Fabiano Scherner vs. Ricco Rodriguez 
Jake Shields vs. Chris Lytle 
Josh Calvo vs. Filipe Braga Costa 
Stephen Abas vs. Alex Canders 
Nate Orchard vs. Guilherme "Bomba" Vasconcelos