Santana coached Dunga when they were both at Vasco da Gama in the 1980s and they also worked together with Brazil's Olympic team. They now come face to face at Ellis Park with a place in the tournament final at stake as Brazil seek to win a second successive Confederations Cup.
Dunga, whose Brazil side start as strong favourites to end the hosts' dreams of glory, expects the match to be far from easy.
"South Africa are improving game by game, but we are ready and waiting for the challenge," he said at his pre-match news conference on Wednesday.
"We want to improve in every game and because South Africa are in the semis they have to be respected. It won't be easy for us -- they are playing at home and they have the greater emotional support.
"But playing the host is going to be good preparation for the World Cup. Every game is different in a tournament, the players need to experience everything."
"As far as me and Joel are concerned, we were together at Vasco, he is a very calm person, knows what he is doing. Every trainer tries to look for the positives in his players, the same applies to him.
"We did not get the best results when we worked together at the Olympic Games but we just had six days to prepare, so taking this into account we did alright."
Brazil won all three of their opening group matches in this tournament, scoring 10 times and conceding three goals. Although they will be without the injured Juan on Thursday, that should not slow their path to Sunday's final.
