Golovkin is unbeaten in 26 fights and has never been knocked down during a professional or amateur bout, but Macklin has insisted that he will be the 31-year-old's toughest opponent.
The Birmingham-based fighter told reporters: "The guys that he has been walking through are 154-pounders. I'm a strong, big-punching 160-pounder.
"That changes things. He is going to have to be more preoccupied with his defence in this fight."
Macklin has fallen short in his previous two world title attempts, losing to Felix Sturm and Sergio Martinez.