Tenshin Nasukawa has vowed to "take down" Floyd Mayweather Jr. in their three-round exhibition bout on New Year's Eve.
Japanese kickboxer Nasukawa and Mayweather will contest what the American described as "a little boxing exhibition" in Saitama.
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Nasukawa is determined to make the most of his nine minutes in the ring with the legendary boxer, who initially retired in September 2015 before returning just under two years later to take on Conor McGregor.
"People in Japan, listen — I will take down Mayweather," said the 20-year-old, who competes in the Rizin Fighting Federation in both kickboxing and mixed martial arts. "You should look forward to it."
Mayweather is taking a far more relaxed approach to what he says will be "the highest-paid exhibition ever" and is not concerned by his lack of activity since stopping McGregor in August 2017.
"It's just another day. Another day like I wake up, take shower, put my clothes on," the 41-year-old said. "Fighting is something I've done for over 30 years, so it's just another day. I worry about entertaining and things, but once the bell rings, it’s always entertainment. So it is about having fun, going out there and doing my best."
He added: "Me getting knocked out or me getting knocked down ... I don't worry about it at all. If that does happen, I mean that's entertainment. That's all we need to see. I mean, I'm sure he’s taking this fight extremely serious, he's working out at this gym. [But] it’s just another day. I don't have to work hard for three rounds. I can basically do three rounds in my sleep. So, I don’t worry about that."