By Miguel Rivera

Former four division world champion Juan Manuel Marquez believes that Kell Brook (36-0, 25KOs) is not a bad fighter, he is undefeated and has shown good things in his career - but even though the fight is at home, the advantages for Gennady Golovkin (35-0, 32KOs) make him convinced that the middleweight king will win by knockout on September 10 in London.

Golovkin's defense of the IBF/IBO/WBC/WBA middleweight titles against Brook was finalized on Friday for the O2 Arena in London.

Earlier this year, Marquez - who hasn't fought since May of 2014 - expressed his interest in returning to the ring against Brook, who owns the IBF welterweight title.

Marquez believes the weight difference and the difference in power will be too much for the fighter from Sheffield. Brook is heading up by thirteen pounds to face Golovkin at the middleweight division limit of 160-pounds.

"It's a difficult fight. Brook has an elusive style, speed, but the important thing here is the difference in weight, they are two divisions apart, and he is not facing an easy opponent, as GGG is a fighter who comes forward and throws punches with a lot of power. It is a tough fight for Kell Brook," Marquez told ESPN Deportes.

"Speed ??is important, but while he's throwing punches with speed he will have to withstand the punches and the power of Gennady Golovkin. I think we must believe that Brook has to be in supreme condition to continue the fight twelve rounds in the manner that he needs to, by using speed and throwing combinations of punches."

"GGG brings a lot of power. The public will play their important role, the fans will be with [Brook], but GGG has gone against other fighters that have been crowd favorites, so we shouldn't place faith in [the fight taking place in Brook's backyard because Golovkin's fights almost never reach a decision]."