Arsenal boss Mikel Arteta admits dropping points is a concern after their draw with Brentford.
Manchester City can now cut Arsenal's lead to three points with a win on Sunday.
Arteta said, "Yeah, but it was the same with Brentford away and with Fulham and Southampton and with a lot of teams we've beaten here, so it's nothing new for us. We know every team has their way of playing.
"You want to improve in every area. We are the third best team in terms of defensive set pieces. We want to be the best. We discussed that today about giving nothing because from the start of play to set pieces this is their biggest strength. I thought we controlled them quite well. I think in that situation we had controlled them, but we hadn't because they were offside and it's always unfortunate when that happens because it costs you points, so set pieces are huge in this league, that's for sure.
"We tried to win today but you see how difficult it is for every team to win consecutive matches. That's why when you look at the table the amount points they have is for a reason. You need to be excellent in everything you do in the matches and you need certain decisions to go in your favour as well. It's a lot of things."