Kell Brook has predicted that he will "shock a lot of people" when he faces unified world middleweight champion Gennady Golovkin.

Brook will move up from welterweight to take on the world's best pound-for-pound fighter at London's O2 Arena, and although he is considered to be the huge outsider to prevail against the Kazakh, the Sheffield puncher feels that the step-up in weight will only make him more dangerous.

The 30-year-old told Sky Sports News: "If you ask any of my sparring partners when I get down to that natural weight of 160lbs, I'm a beast. I'm a different animal. When I'm a middleweight in training, I'm a different animal. What it takes for me to get down to 147lbs is really hard. Anyone who knows me will tell you.

"I'm going to be eating very well in this camp and I'm going to be fuelled for the sessions and able to push myself even more. In this fight I'm going to shock a lot of people and if not bigger than Golovkin, already my strength is proving unbelievable. We're getting results already and we've still got weeks to go.

"I can't wait to test myself because I'm a different kid at a higher weight. I feel so healthy, strong and fit. I'm so excited to see what I can do. We know what we can do in training before we strip down. We're going to shock the world on September 10."

Golovkin had been expected to face Chris Eubank Jr but a potential deal fell through last week.