Arsène Wenger has explained why there have been so many giant-killings in the cup competitions this season.

Wednesday’s opponents, Liverpool, were just one of a number of top-flight teams to exit the FA Cup last weekend after they were beaten 3-2 by League One Oldham.

Wenger, whose side were knocked out of the Capital One Cup by Bradford City in December, says lower-league clubs have closed the gap in recent years.

“First of all I think that compared to 10 or 15 years ago, the physical level of the lower divisions is at the level of the Premier League today,” the manager told the Official Arsenal Programme.

“That was not the case 10 or 15 years ago; you go into extra time with the lower-division sides now and they don’t pack up, they can live with you. The preparation and organisation of these teams is much better than many years ago.

“Then you have a second impact; that the peripheral players of the Premier League teams who get their chance can lack a little competition going into these games.

“Therefore you have surprises, and when you go to these places they are ready for a fight and they give absolutely 100 per cent commitment. That’s why it is difficult for everybody.

“Maybe mentally we underestimate the difficulty a little bit in our preparation,” Wenger added. “Sometimes you see that the stadiums have a really English atmosphere, the pitches are not perfect like we are used to, the dressing rooms are not perfect like we are used to, the crowd is very close.

“It all creates a destabilising atmosphere where you have to prepare mentally before the game.”

You can read the full interview with the boss in the matchday programme for the Liverpool match. Click here to subscribe

The Official Matchday Programme is now on iPad! Find out more

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 Rob Kelly 31 Jan 2013