Claressa Shields has warned big fight rival Christina Hammer that she made a mistake by agreeing to fight her for the undisputed women’s Middleweight Championship.

Shields defends her IBF, WBA and WBC belts, while German-based Hammer risks the WBO crown she has worn since 2010 in the Atlantic City super-fight between the unbeaten pair this Saturday night.

They've verbally torn into each other nonstop during a long build-up that was delayed because of a injury to Hammer.

The Michigan girl said: "Hammer signed up for something she shouldn't have signed up for. She's going to get hurt on Saturday. I love that she has an accomplished record.

"When I beat Christina Hammer on Saturday, I want everyone's headline to say 'Shields nails the Hammer'. It's not a game to me. It's going to be bad for her.

"I think she's shook. She doesn't want to say anything after all the social media talking she was doing. This is her time to say it to my face.

"I'm just being myself. I can't put all the pressure on me to be something I'm not. I love talking trash, that comes natural.

"There's a bit of truth in there too. When it gets to times like this, I'm not afraid to say how I feel," explained the 24-year-old.

Shields-Hammer belts

Whoever wins the most significant women’s boxing match of all time will be on course to rival the likes of Lucia Rijker as the GWOAT. That is a title Shields is keen to grab and will have her supporters for that accolade.

She is a double Olympic gold medallist, a two-weight World Champion and to have Hammer on her CV in her ninth professional fight would be remarkable.

Shields continued: “When you’re saying I’m the greatest of all time I can beat any kind of fighter - a fighter that moves, a fighter who’s standing there, a fighter who can do both.

"Being the greatest woman of all time comes with being able to win those fights.

"Everybody’s like 'how can a person who’s been professional only two years beat a person like Hammer who's [been] a professional 10, 11 years and they’re the reigning Champion for most of them'.

"And that’s what the greatest woman of all time can do. Just like I beat Hanna Gabriels I’m going to beat Christina Hammer."