Arsenal manager Arsene Wenger has said that he is concerned by his side's inability to score from set pieces.
The Gunners have not found the net from a corner this season and saw a number of efforts go to waste during their 1-1 draw against Tottenham Hotspur on Saturday.
"It's a concern," Wenger told the club's official website. "We have lots of room for improvement and we need to do that quickly.
"If you go anywhere in the world and have 15 corners against you, you will concede because they should be so difficult to defend.
"I have a lot of talent at my disposal but Tottenham are a very tall side. Players like Jan Vertonghen and Younes Kaboul are very tall and they defended well."
Arsenal are back in action when they host Galatasaray in the Champions League on Wednesday evening.