Javier Mascherano has urged Barcelona to do away with the assumption that Arsenal will come out and attack them at the Camp Nou, insisting that Arsène Wenger's team are "not stupid".

If there was a lesson from the 1-0 win over Real Zaragoza on Saturday night it is that, although they normally find a way through in the end, Barça can be frustrated by sides that "park the bus". It is a tactic that José Mourinho's Internazionale employed successfully in the semi-final last year but the assumption in the Catalan capital is that Arsenal will not do the same.

Mascherano, though, has warned his team-mates that the London side do know how to play defensively when the situation demands it. The Argentinian, who is likely to start on Tuesday night after it was confirmed that Carles Puyol will miss out, thus forcing Sergio Busquets to play at centre-back, said: "They are not stupid. They have a [2-1] advantage and they will try to protect that lead. They will come to defend. The difference [from Zaragoza] is that, as we know, when they do have the ball they also like to play and they have the players to do that.

"Arsenal know how to defend as well as attack. We can't make the mistake of thinking that, just because they know how to play attacking football, they don't know how to defend. In football when a team plays well we all jump to that conclusion. But if Arsenal have to defend, then they will defend. The problem is that when they have the ball they will try to play football – because of the players and the coach they have."

As for Barcelona, there were fewer doubts. "If there is one good about Barcelona, – and it is something that transcends any game or team - it is that, regardless of whether it is the most important game of the season or not, we play it exactly the same way," Mascherano said.

"That is the way we played in London where, despite the result, we were spectacular. There are games when you don't get what you deserve and you go away with very little reward. But, if we have to go down, then we will go down playing the Barça way."