Chelsea goalkeeper Petr Cech says defeat at Aston Villa was down to bad luck.
Cech saw two goals fly past him from set-pieces, but insists: "We are aware we are conceding to set-plays and we know we have to pay more attention and have better concentration next time.
"But it's not a general problem. This is three goals in two away games, so we need to get our discipline in marking because it can be costly.
"If you finish the season with two defeats, then it doesn't matter if it's the first 20 games or the last 10 games. You have to be consistent the whole season.
"Villa have big lads. In the first half we managed to deal well with the crosses.
"There was a deflection before the first goal. In the second half we didn't mark well. I went for the ball and clipped someone in front of me and that's why I couldn't reach it because usually I would have put it to safety.
"We are not having much luck at the moment."
