The 35-year-old is best known for appearing in reality TV show Geordie Shore but moved into the world of combat sports.
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After clocking up seven MMA fights, he has moved into boxing and was victorious in his only fight - a points win over Alexander Zeledon last year.
Now comes the biggest test of his career against 50-0 fighter Mayweather at London's O2 Arena on Saturday night.
And it appears everyone wants to see the flight live - even Newcastle club captain Jamaal Lascelles whose side will be in the capital for Sunday's Carabao Cup final against Manchester United.
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"My barber was saying that Jamaal Lascelles was on about getting tickets for the fight," Chalmers told talkSPORT.
Laughing, he said: "I'm not sure he'll be able to get tickets for the fight when he's got a big cup final the next day. I don't think that'll go down too well in the media."
Chalmers faces a tall order against the 45-year-old but that has not stopped his legion of fans booking their weekend's in London despite not having a ticket for Saturday's showdown.
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"I'm hoping a lot of people will be tuning in. I know loads of lads are coming down without a ticket to be in London for the weekend, he added.
"I would have bet my house this time last year, me fighting Floyd Mayweather and Newcastle being in a cup final because it would never have happened.
"It's crazy, it's big for Newcastle. I would 100 per cent take the Carabao Cup and sixth place in the league - any day of the week."
Win or lose on Saturday night, Chalmers will be hoping Newcastle can win their first major trophy since 1955 when club legend Jackie Milburn fired the Magpies to FA Cup glory.
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