Geale lost the IBF title to Darren Barker 11 months ago, but despite the defeat to the Brit, Golovkin is anticipating a difficult encounter when the two clash at Madison Square Garden on Saturday evening.
When asked if the Australian would be his hardest bout, the 32-year-old said: "Yes, absolutely, because he has a specific style. He has proved that in his fights and it will be difficult to solve. Daniel is a great fighter.
"I have watched his tapes, and the last fight in particular makes me realize this is not going to be an easy fight."
Unbeaten Golovkin has recorded 26 stoppages in 29 fights while Geale has won 30 of his 32 professional outings.