Tyron Woodley says he's so confident he'll beat Nate's ass if they clash at UFC 219 next month ... he's willing to fight him with a busted shoulder!!!

"If there's any fighter that I think that I can fight with my shoulder not 100% ... it's that dude," Tyron said on "The Hollywood Beatdown" on the TMZ Sports YouTube channel.

Tyron is rehabbing a labrum tear -- but says he's not worried about it one bit.

There's A LOT more -- Tyron talks about the money he thinks he and Nate can rake in from the fight ... and why he's not even a little bit scared of Nate's famous Stockton Slap.

Woodley also tells us if snorting workout powder is a real problem in the bodybuilding community after the death of Rich Piana.