Nacho Monreal has admitted that the Arsenal players are still haunted by their exit from the Champions League last season.

The Gunners were heavily tipped to beat AS Monaco in the round of 16, but a 3-1 home defeat in the first leg contributed to them being knocked out by the French side.

Ahead of returning to the competition this week, Monreal has insisted that Arsenal cannot afford to make the same kind of mistakes that they did last term.

"The defeat to Monaco is a bad memory for us. You have to try to take positives and we look at the way we played in the win in the second leg in Monaco. But it is really difficult when you are two goals down from the home match and then playing away," the defender told The Mirror.

"Our focus is on starting well in the group and getting three points. In the Champions League you don't play too many games, so if you make a mistake you pay for it – as we did against Monaco. We just need to be focused on getting a good start in the competition.

"The Dinamo game will be a big test for us, but if we concentrate on our strengths we can perform well. We know that the favourite in our group is probably Bayern Munich, so we know we need to do well against Dinamo and Olympiacos."

Arsenal face Dinamo Zagreb on Wednesday evening.