Anthony Mundine has added fuel to his already simmering rivalry with Daniel Geale ahead of their much anticipated rematch on Wednesday night, declaring the IBF middleweight champion "ain't sh*t".

Mundine entered a spirited verbal spat with Geale's American promoter Gary Shaw during a media conference on Monday.

"Daniel knows it. When he steps in that ring with me, he knows he's in big trouble. Trust me," Mundine said.

"He's the same fighter as he was when he fought me the first time. He's got more experience and he's more confident, but that's all going to deflate when he's in there with me.

"He ain't going to handle the heat this time. Daniel Geale ain't sh*t."

Geale, who lost a controversial split decision when the pair first met in 2009, said Mundine was in for a rude shock if he expected to be facing the same opponent.

"If he thinks I'm the same fighter, then that is perfect. I know deep down, he knows I'm not the same fighter," Geale said.

"He's in for the biggest shock in the world if he thinks I'm the same fighter.

"Obviously if he fights as well as he talks it's going to be a great fight. I'm looking forward to it. It's going to be a tough fight but with what we've been doing in the gym, I can't see him being able to handle me now."