David Price has been sparring recently with new European heavyweight champion Kubrat Pulev.
Price, who takes on Sam Sexton for the British and Commonwealth heavyweight titles at Aintree on May 19, knows Pulev well from their days as amateurs.
The Bulgarian has moved quickly through the ranks, beating Briton Matt Skelton in only his fifth fight, and claimed the European strap by beating Alexander Dimitrenko last weekend.
However, the heavy-handed Price (12-0) was pleased to find out there was still not much between the pair when they sparred in Berlin last month.
"We sparred a lot in the amateurs. Before the 2008 Olympics we did a lot of sparring and he would get on top of me so I wanted to go back and see where I was now. It was a good gauge," he said.
"We did five spars in all and each one was different and one day I would get the better of him and the next he would have it more his own way."
Price said the trip was a pleasant distraction from the growing media attention as he prepares for his biggest fight yet against Sexton.
"I needed to get away because there are a few distractions at home in the city," he added. "A lot more people want me to be here, there and everywhere.
"It is nice to know you are in demand, but training is the most important thing so I had to get away and focus.
"Just a few different things were getting in the way of my preparations. It has done me the world of good. There was nothing there apart from the hotel and the gym so there was plenty of time to focus."
The Olympic bronze medallist heads a huge night of boxing for Liverpool on Saturday week when the home town could have two British champions and a Commonwealth champion.
"It's an honour to be part of history, breaking new ground at Aintree, and if I can be the first British heavyweight champion from this city on that night it will be brilliant," said Price, who feels a boxing renaissance in the city has been a long time in the making.
"It dates back to 10 years ago in amateur boxing, the ABA champions in the 2000s, a lot of them came from Liverpool and we've all turned pro at similar stages over the past five years or so.
"It's coming to a head where they're all fighting for titles so I think a lot of credit needs to go to the amateur set-up which has been brilliant, and I think it was inevitable to be honest."
Promoter Frank Maloney said he was proud to be involved with so many promising young fighters from Liverpool.
"One side is full of home fighters and it shows the strength in depth of boxing here in Liverpool," he said. "We will continue to build and continue to bring success.
"It's a great night and it's a city full of promise. This is a very even card and it's important to give good value."