Derek Brunson Calls Out Darren Till, I'll Whoop Dat Ass!!

"Imma whoop Till ass, ain't no bones about it."

That's Derek Brunson -- fresh off his UFC 241 win over Ian Heinisch -- declaring to TMZ Sports that he'd beat Darren Till to a pulp.

"It ain't no beef, it's just business at usual, you know? Darren Till looking to move up to middleweight. He's a top guy. Fought for the title at welterweight. I feel it'd be a good challenge. A guy with a lot of hype behind him. I think we should definitely mix it up next."

Brunson is a 35 years old UFC vet who's been with the organization since 2012 and has messed up dudes like Lyoto Machida and Uriah Hall.

Till -- a 26 year old fighter from Liverpool -- is coming off the only 2 losses of his career (Tyron Woodley & Jorge Masvidal) ... but is still regarded as one of the baddest, brightest young stars in the UFC.

That's why Brunson wants this fight.

"It ain't I'm calling Till out cause I think I can just beat him up. I think I can beat everybody, but it's also about fights that make sense. Big fights, stuff like that."

Derek's dead serious about makin' this happen ... he already has his rep, Ali Abdelaziz, working on making the match.

"My agent reached out," Brunson told us ... "I'm yet to hear from [Till]."