By Chris Harris

Arsène Wenger knows that Arsenal will need a flawless defensive display to fend off Barcelona on Tuesday.

The Frenchman takes his team to the Nou Camp this week for the decisive leg of a Champions League last-16 tie that his side leads 2-1 after a thrilling victory at Emirates Stadium last month.

Arsenal lost 4-1 in Barcelona last season to succumb 6-3 on aggregate in the Quarter-Finals but, on that occasion, Wenger was without two centre backs plus his strongest defensive midfielder, Alex Song.

Thomas Vermaelen will not be fit in time for Tuesday but Wenger should have more options this time and he thinks it could make the difference. Not that Arsenal will look to sit on their slender advantage.

"It will be very important for us to defend well because when you go to the most effective attacking team in the world, you want to have your best defenders available," he said.

"We will look to defend well and attack well. We are not a team that will refuse to attack, we know that.

"The challenge will be to find the right balance between having a team who can defend, as well as one that has a good opportunity, every time it has the ball, to go forward."

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 5 Mar 2011