UFC middleweight champion Adesanya is set to defend his title against No.1 contender Costa at UFC 253 in September.
The pair of undefeated MMA stars have developed a genuine beef with the Brazilian fighter poking fun at his upcoming opponent's new hair.
'The Last Stylebender' dyed his hair neon pink ahead of returning to the Octagon, taking to social media to show off his new hairdo.
And Costa pulled no punches in his assessment of Adesanya's stunning makeover.
On Twitter, he wrote: "The only thing more disturbing than this video was your fight against Romero.
"Somebody tell USada to test him for too much estrogen."
The only thing more disturbing than this video was your fight against Romero.- Paulo Costa ( Borrachinha ) (@BorrachinhaMMA) August 9, 2020
Somebody tell USada to test him for too much estrogen https://t.co/RbsklkN73H
Of course, he's referring to Adesanya's underwhelming victory over Yoel Romero at UFC 248 in March.
Costa, who hasn't fought since his 'Fight of the Night' win over Romero at UFC 241 last August, doesn't plan on shaking Adesanya's hand after knocking him out.
"Even after I knock him out, I will not shake his hand," he told MMA Junkie.
"It will be wild. It will be savage... I believe in the second round (I will knock him out) because he will run a lot in the first round."
Meanwhile, UFC 253 is tentatively scheduled for September 26 with 'Fight Island' set to host the middleweight title bout.
"We'll be announcing (the location) soon. But obviously it's looking like Fight Island," UFC president Dana White said.
"A lot of the big fights that are international are going to be on Fight Island. I told everybody the last time we were there, people sort of thought this was a one-and-done or whatever, it's not.
"We're going to be at Fight Island. Abu Dhabi is going to end up being the fight capital of the world. It definitely isn't Las Vegas."
Featured Image Credit: Instagram/YouTube
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