The Blues lost 3-2 to the Premier League champions in the Community Shield on Sunday, in the final game before the new season gets underway.
The Czech Republic international believes that the sending off of Branislav Ivanovic changed the game but that the FA Cup and Champions League winners can still take good points from the match.
"We had quite a good first half, we went 1-0 up and it was an equal, interesting game for the first one of the season, but then unfortunately the red card happened and in the second half they took advantage of having a man more," said Cech.
"We now have the most unfortunate international break, which is not ideal but the players go off, then we come back and the season starts on Sunday.
"We can take positives from this game but hopefully next week we will be fitter and sharper, Manchester City was a step forward and I am sure we will be ready for Wigan."
Chelsea travel to Wigan Athletic in their Premier League opener on Sunday.