Tunyiswa, who is a training partner of former New York Marathon winner Hendrick Ramaala, will wrap up his preparations this weekend.
"The Nelson Mandela Marathon has been on my calendar for this year. I have been preparing for it with Hendrick and Zongamela Dyubeni," said Tunyiswa.
"It forms part of my preparations for the City to City Marathon that I will be defending in Gauteng on September 30. So far, so good in terms of everything.
"I won't put myself under tremendous pressure because for me the bigger picture will be the City to City Marathon. I want to make it two in a row," he said. "Zongamela will be going to Pietermaritzburg with me; he will use it to prepare for the Soweto Marathon."
Dyubeni, who, like Tunyiswa is a member of the Nedbank Athletics Club, is excited to be taking part in a marathon named after Madiba. "I have decided to be there because the event is named after Madiba, but also to support Odwa as one of my training partners. The big race that I'm preparing for is the Soweto Marathon," he said.
The event has also attracted local running legend Bruce Fordyce. Fordyce is a household name, having completed a staggering 30 Comrades Marathons and having won nine.
Fordyce famously wore a black armband in his first Comrades win in 1981 in protest against apartheid, and was pelted with rotten tomatoes by a fellow runner for his action, but Fordyce describes it as "one of the proudest moments in my life".
Fordyce will also act as a brand ambassador to publicise the event.
The race starts in Imbali in Pietermaritzburg, outside the hall where Mandela delivered his famous speech in 1961, and ends near Howick at the site where he was stopped and arrested at a roadblock.