Joe Hart, Joleon Lescott, Gareth Barry and James Milner all started Tuesday night's 3-1 triumph in Switzerland, and they were joined off the bench by wingers Shaun Wright-Phillips and goalscorer Adam Johnson.
Never before have so many Blues worn the Three Lions in the same team, and smiling manager Mancini told City's website: "It was very important for the club because it is the first time there have been six of our players.
"It has happened in Italy before with Juventus players, but I think it is unusual here in England. For England to have six City players is something everybody at the club is very proud of, myself included.
"I am happy for them because all these players deserved to be in the England team, because they have worked very well this last month and in pre-season, and they have had a reward for that."