Joe Calzaghe will make the 20th defence of his WBO super middleweight title against Peter Manfredo at Cardiff's Millennium Stadium on Saturday 3 March.
Manfredo, 26, finished as runner-up on US TV series 'The Contender' and holds a record of 26-3 (12 KOs), but has not met anyone in Calzaghe's class.
The bout is set to cost unbeaten Calzaghe, 34, his IBF world title.
The IBF have said they will strip the belt if the Welshman does not face Robert Stieglitz by December.
German-based Russian Stieglitz, 25, has an unbeaten record of 29-0 (19 KOs), but there are no major names on his record and he is unattractive to the American television companies.
I want to thank Joe Calzaghe for giving me the opportunity of a lifetime. But it's time for a change. I'll be going over there hungry
Peter Manfredo Jnr
Calzaghe is unfazed by Manfredo's threat that he will be the one to end the Welshman's long WBO reign.
"He's well known in America and a tough kid, but this is my 20th defence and ninth year as champion, and he is not going to spoil that," said Calzaghe.
"There is a world of difference between being a reality TV star and a world champion boxer.
"He has only seen the glitz and glamour of the sport - now he is in for the real thing."
Manfredo told BBC Sport: "Calzaghe has defended his title 19 times, but he's got to lose at some point and he's going to lose this time."
He now holds career-high world rankings of number seven by the World Boxing Organization and eight by the World Boxing Council.
The Rhode Islander describes himself as a boxer who "likes to bang and mix it up" and believes his hunger for a world title will prove decisive.
Is the Manfredo fight purely so the Americans know who he is...and will he win?
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"The only Calzaghe fight I've seen is the one where he beat up Jeff Lacy," said Manfredo. "He looked like the champion he is.
"I didn't see his last fight [a scrappy points win over Sakio Bika in October], but everybody has good and bad fights.
"But I'll be coming over to win. I feel good about the fight and I feel good about myself.
"I want to thank Joe Calzaghe for giving me the opportunity of a lifetime. But it's time for a change. I'll be going over there hungry.
"If people want to make some money on the fight, they better put their money on me because I'm going to win."