The Ghanaian with a reputation for speaking his mind claims Fifa is killing the game on the continent but an official in Nigeria claims he is just an alarmist.
Ghana will play Nigeria in the semi-finals of the championships but moments after his side beat Togo 2-1, Duncan claimed artificial pitches were a real strain on the players.
He said: “Apart from the fact that playing on synthetic pitches does not fit into African football, the turf itself is a big risk health wise to our players. The heat being generated from the materials used in producing the synthetic pitches is bad.
"Even when we play on natural grasses, we have to wait for evening because of the heat. So why is Fifa bringing synthetic pitches into African football?
“As I said, Fifa is in Europe and they should set such standard in Europe first before bringing it to Africa.”
But Duncan's criticism of the artificial pitch drew a stinging rebuke from Ogun State governor Bukola Olapade.
Olopade does not see any sense in Duncan’s argument, saying: “The man [Duncan] is an alarmist and I want people to disregard what he is saying concerning synthetic pitches in Africa. Fifa said the reason for introducing synthetic pitches into Africa is to develop our football.
"Playing on synthetic pitches make the game fast and that is what Fifa is preaching. Look at the Togolese team and their fast pace on the pitch.
“Is this coach saying that he knows more than Fifa? The 2007 edition of the Under-17 World Cup, which the Golden Eagles of Nigeria won in Korea, was played on synthetic pitches. Even Ghana's Under-20 team played on synthetic pitches in Canada and got to the semi-final.
“Ever since Ghana came to Abeokuta for this Wafu Nations Cup competition, Coach Duncan has been looking for a way to cause confusion.
"He rejected four hotels the LOC provided for his team. If his team is not good enough for the trophy, Duncan should look for better excuses rather than fault our facilities.
"I don’t think that Ghana has better hotels than Nigeria. I have been to virtually all major cities in Ghana and I know what I am talking about.”