The Citizens slipped to a 1-0 defeat thanks to an effort from Adam Johnson, who left the club during the summer.
City enjoyed greater possession and shots, but were unable to breach the Black Cats’ defence.
After the game Mancini was adamant that his team deserved to take at least a point from a game in which he felt they were the better side:
“When you come to play here you say the same things, you dominate the game and you lose, you don’t think it is possible but this is football,” he told Sky Sports.
“It is the same as last season, like two years ago, like three years ago.
“I think we played very well, but we had one problem – we need to score and we don’t score enough to win, and at this time our strikers need to improve, if you don’t score you don’t win – we had five chances in the first half and did not score.”
The Italian was also critical of referee Kevin Friend for missing what he thought was a foul on Pablo Zabaleta in the build up to Johnson’s goal:
“You need to ask referee and linesman,” he responded when asked about the legality of the strike.
“I was there, there was not a foul but a big foul – maybe the referee had too much for Christmas.”