The reigning champions lost top spot to neighbours Manchester United due to the result and the way they went about it this afternoon, especially in front of goal, left a lot to be desired according to the Italian.
"I think we play very well but are missing a goal," Mancini said.
"We had a lot of chances but were missing the last pass or shot.
"When you are near the box you should be very strong, if you are soft you cannot score.
"We dominated the first half, second half Chelsea did better, but we need to be strong, we were too soft."