"Yes, I will definitely be there tomorrow," Daryl Peense told Sapa ahead of Saturday's event at the Greyville racecourse.
"I suggested this year they give me a sippy cup so that I don't have any spillage this time," he said, referring to a child's spouted drinking cup.
In November 2011, Peense spilled his drink on Zuma and was arrested at the event.
He was later found guilty and fined R8000, suspended for three years, by the Durban Magistrate's Court.
During his trial, Peense denied deliberately spilling his drink on the president, claiming it spilled when people pushed against him to get a better view of Zuma.
He claimed he was drunk at the time and was standing over a balcony when this happened.
It emerged during the trial that the spilled drink had not touched Zuma as a bodyguard had shielded him.
On Friday, Peense said he would be sitting at the same spot as he did in 2011.
"I'm in the same place I was the last time. I sit at the same spot every year, just above the parade ring," he said, predicting that horse number 14, Captain America, would win the race.
The presidency said Zuma was expected to attend the event, but that this could change without notice.
Quipped Peense: "I probably won't even see him [Zuma]... But today I'm in a state of sobriety, tomorrow I might not be."