Zwane was guilty of missing a penalty during his team's defeat in the DStv Premiership at the Harry Gwala Stadium on Saturday.
The Brazilians had a chance to double their lead in the 84th minute but 'Mshishi ' saw his spot-kick saved by Marcel Engelhardt.
"I think he was unfortunate. He has been one of our most reliable penalty takers and we can't know that he missed this one and want to blame him," said Mngqithi during the post-match.
"Honestly speaking I think we will be unfair to him, he is one of our most important players. And we gave him the penalty because he scored a lot of penalties for us, it's not like we have just picked him because he is our favourite.
"We must forgive and understand that at times in football you score some and you miss some, you cannot really blame him for that," he added.
Besides Themba Zwane, Mamelodi Sundowns used to rely on Brazilian defender, Ricardo Nascimento to score penalties for the past few seasons.