By Nick Teale

Arsène Wenger has admitted that Arsenal must "add something" in defence because his side look vulnerable in the big games.

The Gunners have failed to take points from title rivals Chelsea and Manchester United this season and Wenger's side have also suffered defeats on the road at Manchester City and Tottenham Hotspur.

The manager has defended his side for their North London derby defeat, citing injury problems. However, he has also conceded that he must strengthen his backline in order to compete with the best.

"On the same night [against Tottenham] we did not have Gallas, Fabregas, Van Persie and Arshavin," he said. "It is not easy if you take four players of that calibre out.

"But we need to add something. I believe defensively in the big games we were too vulnerable."

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source 16 Apr 2010