Chelsea boss Roberto Di Matteo believes the red card issued to Branislav Ivanovic cost his team the Community Shield.
The Blues were leading 1-0 at Villa Park thanks to Fernando Torres' first-half strike but eventually lost 3-2 following Ivanovic's sending off for a studs-up challenge on Aleksandar Kolarov.
"It changed the game in favour of Manchester City," said Di Matteo. "We competed very well and at that point were in the lead.
"It was difficult in the second half against 10 men.
"The challenge had no intent to hurt the opposition. It was a sliding tackle and he got the ball as well.
"Sometimes a red card is given in those circumstances, sometimes it is not. But there was no intention to harm the opponent."
Di Matteo was happy with the performance of £32million signing Eden Hazard as well as the efforts of Torres but acknowledges it will require a team effort to make up for the departure of Didier Drogba.
He said of Hazard: "He was lively, caused a few problems, had a couple of opportunities, we saw glimpses of his quality, and he will be a big success for us.
"Fernando was also dangerous in what was his first 90 minutes since coming back into training under three weeks ago.
"But we have to share the responsibilities for goals between the team - Hazard, Torres, Ramires, (Juan) Mata, (Daniel) Sturridge, (Frank) Lampard can all score goals."