Gervinho told the club's official website: "These games against opponents for the title, we can't afford to lose them, especially at home. They count a lot in a season.
"We had a great team against us, with great players, technical players. Chelsea managed to keep the ball well and caused us problems.
"It would have been great for us to win it but we had no luck and we were not as good as our last game. It's a big disappointment. But we need to swallow this defeat and to focus again on Wednesday's game, because that is another big game."
Attention in north London turns to the Champions League on Wednesday, when Arsenal host Greek Super League winners Olympiakos.