South Africa defeated their bitter rivals in the final of the World Test Championship more than a year ago at Lord’s, and Harmer believes the sting from that loss will fuel their opponents’ vengeance.
He says while most of the players are teammates in T20 franchises around the world, the red ball rivalry will be renewed once the first ball is bowled at Kingsmead.
"I think it was almost a foregone conclusion that Australia were gonna win that game but the team found a way to get through it and to get the win. I'm sure Australia wants sort of a bit of revenge from that loss and I expect them to come out firing and being competitive,” Harmer said.
“I think the nature of T20 cricket, you are playing with a lot of players a lot of the time.
“I think one is the days where you sort of had these huge rivalries where you will play against one another every 18 to 24 months, and it created that sort of Oogie Boogie on the field.
“I think T20 has softened that a little bit but I don't expect them to be softened by any stretch of the imagination."
The Proteas defeated the Aussies in the first match of the recently concluded ODI series at the same venue and Harmer says while the visitors were outmaneuvered there, Test cricket is a completely different kettle of fish.
"I think based on the one day series, I didn't play it as well as they probably would have wanted to but I think the test is a completely different kettle of fish. I think there's different personnel that come into the test setup,” he added.
“So, from my perspective I can only focus on what's there and there's not too many transferable players other than the one day setup. So, I hope they don't play it well but we are expecting them to play it well.