IBF, WBC, WBA middleweight champion Claressa Shields has rejected the claims being made by Savannah Marshall, who says the two-time Olympic gold medal winner was running from their unification clash.

Their showdown will draw closer in December, when they appear on the same card in separate fights. The card takes place on December 11 in Birmingham.

Should they both win, their showdown will take place take place in early 2022.

Marshall is the only boxer to defeat Shields - when the two were amateurs. Shields was 17 at the time of that fight.

Marshall claimed that Shields ran off to mixed martial arts to avoid their meeting.

"Savannah Marshall is a liar. When I first signed the contract to fight for the PFL [in mixed martial arts] she made it all about her. [She was saying] 'she's running from me, she's scared of me' but I never retired from boxing. I'm still the owner of three belts. The only reason she is WBO champion is because I had to vacate that belt to fight for undisputed championship at 154lbs. Other than that I would still be undisputed at 160-pounds," Shields told BBC.

"She didn't fight the champion to get the belt. Her and [promoter] Eddie Hearn whined and cried about it. They made tears about it and the WBO said I had to vacate. She just makes everything about her and it's not. Her whole career is based off of me. I'm 26 now, what have you [Marshall] done in that time span? You were signed to Floyd Mayweather, did you make a name for yourself in the US? No. The only thing she can say is she beat Claressa Shields when she was 17. That's it. Other than that, what else has she accomplished in her career?

"When we fight, then they'll see what real power is. In her last fight, she lost the first round. Let's just be clear, she lost the first round. She didn't know what to do when that girl was on her like white on rice. That's going to be me times a hundred and I don't gas out. We all know that. I don't gas out. I've got the skills. I've got the stamina. I've got the speed."