By Jose Luis Camarillo, notifight.com

Trainer Abel Sanchez is expecting a very tough fight when IBO/WBA/WBC/IBF middleweight champion Gennady "GGG" Golovkin (35-0, 32KOs) defends his titles against Kell Brook (36-0, 25KOs), the IBF's welterweight champion.

Golovkin vs. Brook is scheduled to take place on September 10th at the O2 Arena in London.

The first opponent in the running was British middleweight champion Chris Eubank Jr. Those talks fell through when Eubank was unable to reach an agreement with his promoter, Eddie Hearn of Matchroom Sport.

Brook is also promoted by Hearn and accepted the exact terms that Eubank rejected. Brook fights thirteen pounds lighter and is moving up by two full weight divisions to challenge the middleweight king.

"The goal of Golovkin is to become the middleweight champion of the four organizations, but the title of the WBC was the most important. Now he'll continue making history and defending his WBC belt, the WBA and IBF, and in the future he will win the WBO as well," Sanchez said.

"We're facing Brook because there are very few fighters willing to fight Golovkin. They say yes, but want to wait and keep talking. Golovkin is 34 years old, and he needs to fight 3 or 4 times a year, so the negotiations had to be quick. This deal was done because Eddie Hearn is the same promoter of Brook and Eubank," Sanchez added.

"Eubank would not fight and demanded things that could not be done. [Once Brook came in], they just had to change the name and photo on the posters. Brook is a world champion. For me, the fight is more difficult than the one with Eubank because we're going against a fighter who has never been beat. He's never been knocked out or hurt like Amir Khan was with Canelo."