Hart does not believe that there was too much between the two sides, but has admitted that his team struggled to create chances over the 180 minutes of European action.
"We could easily be in the final, but they managed the game well. They got a very lucky goal," Hart told BT Sport.
"They created very little over the two legs, so did we in fairness. It was close and we came off the wrong side of it. We defended well, but we just did not have that little bit more. Did we do enough to win the game? I don't know."
Man City had reached the semi-finals of the Champions League for the first time in their history.