Details of the former Transnet School Of Excellence coach are still sketchy.
"I'm not really sure what took him, they are saying he couldn't breathe this (Tuesday) morning," Isaacs tells snl24.com/kickoff.
"Sometimes there are more questions than answers, he played a huge role in my football career.
"When I went to School Of Excellence in 1995 coach Mandla was there with coach Cavin Johnson and Sam Mbatha.
"They really played a magnificent role in my football career and my football knowledge.
"There was a time when I was really struggling, you know when you take an 11-year-old from Cape Town to Joburg where he experienced a language barrier, and I was playing in a group two years my age.
"But then coach Mandla said 'No bring Dominic to my group', then I was playing in my own age range then I found my feet, and two years later I was in the Under-17 national team, at 14 years old.
"So I have a lot to be grateful for, coach Mandla never had any favourites, we never saw him angry he was always smiling, teasing you, asking how's your family doing.
"People like coach Mandla, Sam Mbatha, Thabo Dladla, Farook Abrahams, Cavin Johnson... These are coaches that went and studied overseas and came back and developed players at the grassroots.
"But because of the way football is run they will never get the recognition they are supposed to get.
"We are not utilising them and age is against them, we always go to the AFCON and World Cup and each time we come back we complain about not taking development seriously, but nobody is putting the plan into action.
"So coach Mandla is one of those unsung heroes that never really got recognition.
"If we were to have one of those School Of Excellence in each of the nine provinces, wouldn't that be good?
"So ja, when I heard the news this morning I was crying, crying, crying... You know what? He made me a defender.
"I ended up being a defender because of coach Mandla. Before that, I was a midfielder-cum striker."