Mancini has been dismayed by what he views as an over-the-top reaction to De Jong's tackle on Hatem Ben Arfa during City's win over Newcastle a fortnight ago that left the young Frenchman with a double leg break.
"Probably people do look at things negatively but every week, in every game, here, in Spain, in Italy, there are unbelievable fouls, worse than Nigel," he said.
Although the incident went unpunished by referee Martin Atkinson at the time and the Football Association have decided not to take further action, Ben Arfa's parent club, Marseille, are threatening to sue, while a number of former professionals have launched into De Jong.
Most damaging of all, the midfielder was axed from Bert van Marwijk's Holland squad as a direct consequence of his conduct, with the accompanying suggestion that De Jong starts to look at the way he behaves.
Coming on the back of his X-rated World Cup final tackle on Xabi Alonso, De Jong is beginning to develop an unwanted reputation.
And Mancini accepts this might mean his career might be viewed negatively.
Yet the City chief believes such a perception is undeserved.
Mancini said: "I remember that foul in the final very well. He was late in the tackle. He started and couldn't stop.
"But he is an honest player. He is a hard player but there are a lot of players like that and I am very disappointed with all the people who have spoken about this situation."
Source: PA
Source: PA