Cech fears Chelsea's failings in front of goal could come back to haunt them next week.
He said: "We ended up with the worst result and the disappointing thing is we haven't scored.
"We had the better chances and I hardly had to make a save all game.
"I can't tell you whether it was a penalty or not. I just saw Ryan running with their guy and suddenly he was on the floor.
"We have made it hard but 1-0 is not a scoreline which can't be overturned."