Shields will make her UK debut next Saturday on February 5 in Cardiff, live on Sky Sports, against Ema Kozin on the undercard to Chris Eubank Jr vs Liam Williams.

She said about training with the retired superstar with the 50-0 record: "Training with Floyd Mayweather has pushed my confidence even higher.

"He's very fond of my skills and my power and he said he's going to fly to the UK to watch this fight.

"So I'm definitely looking to put on a great show.

"If I had to use one word for this camp, it would be: uncomfortable. I made sure that I got out of my comfort zone for this fight. I'm making sure that I have all my tools and going to the Mayweather Boxing Club has really sharpened those tools."

If Shields retains her IBF, WBA and WBC middleweight championships against Kozin next week she will edge a step closer to facing WBO champion Savannah Marshall in the biggest women's boxing match ever.

"I've never overlooked an opponent and I won't just because of the Savannah Marshall fight," she said.

"We've always had someone that we're already working on facing for the next fight. I've been in this situation before. I'm focusing on the person who has earned the right to fight me. Kozin is my mandatory, and I respect that this is a huge opportunity for her.

Shields has won back-to-back Olympic gold medals - at London 2012, she triumphed as a 17-year-old.

"I'm expecting the UK fans to be very excited to see me," she said.

"When I walked out there in London for my gold medal match in 2012, it was an explosive crowd. They have great fans and I'm excited to be back to show off all my improvement since 2012.

"I'm going to bring my world championship experience to this fight. She has more fights as a pro than me, but she has not fought the top-tier champions like I have.

"That's definitely to my advantage in this fight. She's going to see my experience in this fight and see that it's totally different at this level."

Sky Sports Boxing schedule

Sunday January 30 in Tulsa
Robson Conceicao vs Xavier Martinez - WBC super-featherweight title eliminator
Nico Ali Walsh

Saturday February 5 in Cardiff
Chris Eubank Jr vs Liam Williams
Claressa Shields vs Ema Kozin - IBF, WBA and WBC middleweight titles

Saturday February 19 in Manchester
Amir Khan vs Kell Brook
Frazer Clarke's pro debut

Saturday February 26 in Glasgow
Josh Taylor vs Jack Catterall - undisputed super-lightweight titles
Nick Campbell vs Jay McFarlane - Scottish heavyweight title

Saturday March 5 in Fresno
Jose Ramirez vs Jose Pedraza

Sunday March 20 in New York
Edgar Berlanga vs Steve Rolls
Keyshawn Davis
Xander Zayas