Greg Hardy's got a message for Dana White on the heels of his 32-second KO debut -- "keep an eye on me" ... "'cause you're gonna want me in the UFC eventually."
"I'm here to prove whatever I need to prove," Hardy told TMZ Sports .
"I'm trying to work on being the best me that I can be -- being the best athlete, being the best complete fighter, being the best person."
Pretty good pitch for the embattled ex-NFL star -- who Dana says is gonna have to conduct himself like a pro in and out of the cage before he gets a UFC opportunity.