The Blues were unable to defend their 2009/10 title, eventually losing out to Manchester United after a poor spell in the mid-stages of the campaign.
Cech acknowledged that it is difficult to win everything you play for but suggested that the London club were indeed disenchanted with the way they performed.
"In the last two months we had been winning and you could see the team had the quality to defend the title, but unfortunately that dip in December and January cost us," he told Chelsea TV Online.
"You know that you can't win everything all the time, but on the other hand with the quality we had, we had much more potential to be fulfilled this season, so that is always a disappointment."
And the Czech international said the sacking of assistant Ray Wilkins in November did not contribute to the Blues' downfall.
"Ray leaving must have been a bit of a coincidence as well, because you cannot just blame the departure of one coach on everything which is not right because the manager stayed, the other people were here," he added.
"The quality of the training was the same, the players were the same and it did not work, so it is not only about one person leaving the club, although everybody liked Ray.
"It was about us not performing well and it took us a while to come through that, which can happen - but unfortunately not if you want to win something."