By Joe Brewin                 

Arsène Wenger has warned his players against complacency ahead of their Champions League clash with Olympiacos.

The Gunners face the Greek champions in their first Group F match at Emirates Stadium on Wednesday and the boss believes taking any side lightly in this competition is a recipe for disaster.

“For me, it is difficult to beat anybody,” said Wenger. “We have a lot of respect for Olympiacos. I have seen their game against Marseille and they played well.

“You never win easy in the Champions League - when you give absolutely everything, you have a chance to win.

“If we have not learned that from 14 consecutive years in the Champions League, then we are really stupid. If you do not prepare properly, then you have no chance.”

The Gunners have impressed in the competition so far with strong performances against both Udinese and Borussia Dortmund. And Wenger believes their form in the Champions League can aid their chances of success in the Premier League.

“Any victory will help us,” he said. “I have always been optimistic because I feel that the players are mentally strong and focused.

“I am impressed by the quality of all the players we brought in, not only on the football pitch - that I knew, but also their mental attitude is absolutely fantastic.

“That's why even before the Bolton game I was very positive about our future. But that is what's at stake for us - to show we can deliver week-in week-out.”

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 27 Sep 2011