According to promoter Eddie Hearn of Matchroom Sport, there were no issues in making a deal for a showdown between IBF, WBA, WBC and IBO middleweight champion Gennady Golovkin and IBF welterweight champion Kell Brook , which is scheduled to take place in London on September 10.

The bout, which will see Brook step up to middleweight, was finalized after the Sheffield fighter had been expected to face off against WBO champion Jessie Vargas at the city's Bramall Lane stadium. But that contest was shelved as the two undefeated stars prepare to meet at the O2 Arena.

Golovkin was heading into a fight with British middleweight champion Chris Eubank Jr. - but that fight fell apart after the boxer and his father/manager, Chris Eubank Sr. made unrealistic deamnds, according to Hearn.

When Hearn saw the fight between Golovkin and Eubank falling apart - Brook entered the picture.

"We were in talks for two separate fights between Chris Eubank Jr. and Gennady Golovkin and also for Kell Brook in a unification clash with Jessie Vargas. The Eubanks were given a deadline for the fight and chose not to accept it," Hearn told Sky Sports.

"Then all of a sudden I was on the phone to Kell Brook and I said 'it's a shame you aren't a middleweight, you could fight Golovkin' and he said 'I'll fight Golovkin'. I asked if he was serious and he said 'absolutely, sign me up.' Twenty-four hours later he signed the deal and he is fighting the most dangerous man on the planet, the number one pound-for-pound fighter in the world."