Arsenal boss Arsene Wenger has demanded that his players believe they can overturn a four goal deficit to AC Milan going into Tuesday night’s Champions League last 16 second leg.The north London side trail from the first leg after being soundly beaten at San Siro two weeks ago and looks likely to be heading out of Europe’s top competition.However, Wenger insists although the club hasn’t given itself an easy situation to deal with, it still has a chance of progression if the players have belief.“We do not have to speculate on any weakness of Milan because they are a good side, but we know only one thing gives us a chance and that is to give a top-class performance," Wenger told reporters.“That is what we will try to put in. The task is a high one, the level of performance demanded is high, but we want to be top-level performers."He added, “I said I don’t live in a dream world – that means I know we have not created an easy situation. Statistically, we have a five percent chance, because if you look at the history of results that have been changed at that level, it would be around that."“But what is important is that we believe we can be in this five percent. Let’s make sure we do not miss our chance because we did not believe in it.”The Frenchman has made no secret of his disappointment from the first-leg and admits it was hard to find the positive after the loss.“That’s the first time we’ve lost 4-0 away from home in a Champions League tie,” Wenger added. “It was a massive disappointment.“We have been poor and have to face the truth. I include myself in that. I felt as poor as the players were on the night. I have always said the mentality in this team is very good but on the night I’m sorry that we didn’t turn up.”The 62-year-old is also keen to use the momentum the Gunners have found since the defeat in Italy, especially the 5-2 comeback over north London rivals Tottenham.“It is not an argument for us,” said the Frenchman. “We want to have a real go, we want to make it possible.“We will not accept going out of the Champions League because we want to stay in. We will give it our best shot.“The best way is to ignore the first game and do what we did against Tottenham - we were 2-0 down and just kept going. That’s what we want to do again."But I know my players. They have been hurt and they have their pride. They will give a performance.”