Chelsea have lost their last two matches on the road this season - to Wigan and Aston Villa - while six of their last eight goals conceded past Cech have come from dead-ball situations.
"The last two away games we've conceded three goals from set plays so we need to get our discipline with marking and avoid these goals, because they can be costly," Cech said.
"At the moment we are a little bit unlucky as well, but we know we have to pay more attention and have better concentration next time."
The weekend defeat at Villa Park saw Carlo Ancelotti's side surrender top spot to Manchester United, but Cech says Chelsea will bounce back if they can return to winning ways.
"It is a pity we gave Man United the chance to go a point ahead but the most important is always the correction," the Czech Republic 'keeper said.
"We have another game on Wednesday and then Blackburn at home and we need to make sure we win those games.
"If you finish the season with two defeats it doesn't matter if they are in the first 10 games or the last 10 games. These two defeats we will judge at the end of the season if they were really costly."