Former champion Wladimir Klitschko has said sparring with Britain's Anthony Joshua a few years ago has given him an idea of what to expect ahead of their world heavyweight title clash at Wembley Stadium on April 29.
Ukrainian Klitschko, who invited Joshua to a training camp in November 2014, was impressed by the London 2012 Olympics champion's attitude and athleticism but insisted that both fighters had benefited from the sparring sessions.
"It's an advantage on both sides. We have sparred and we have been in the ring together," the 41-year-okd Klitschko told British media in the build up to his bid to hand defending IBF champion Joshua a first defeat as a professional.
"He got a chance to look and be in the background of my training team, my camp and got to know a lot," he added.
"I was there in the arena in London when he won Olympic gold. Every medallist... at the Olympics has to be considered successful."
Klitschko, who went unbeaten for 11 years before losing the belts to Tyson Fury in 2015, has 64 wins against four defeats and will be hoping to seize Joshua's IBF crown as well as the vacant WBA and IBO titles that are also up for grabs.
The Ukrainian said he had learned from his mistakes during the Fury defeat but accepted he would never get revenge after their rematch was called off for the second time last September when the Briton was ruled medically unfit to fight.
"I lost, I didn't do enough to win. I was thinking about it for a year, trying to get this rematch," he added.
"And then when it all went downhill... I don't care about it anymore."
Watford-born Joshua has taken the division by storm since turning professional in 2013, winning all 18 fights inside the distance with the upcoming bout expected to draw 90,000 spectators to Wembley.