The Portuguese side lead 2-1 from the first leg, which they won after a highly-controversial quick free-kick. Porto have lost all six of their trips to London - including a 1-0 loss at Chelsea in this season's group stage - and went down 4-0 to the Gunners during September 2008. However, Ferreira believes Tuesday night's encounter, in which Arsenal must do without injured captain Cesc Fabregas, will be different. Porto have plenty of options in attack - with Colombia forward Falcao, Argentinian Marian Gonzalez, Uruguay's Cristian Rodriguez and Brazil international Hulk all pressing to be included in the three-man frontline. "We know what our qualities are and we are confident," Ferreira said. "This will be a very difficult match, but we have the weapons which make it tough for Arsenal. "You need to be able to adapt tactically, but we are always playing to win. "We will try to do the same what we did at Estadio do Dragao." Ferreira added: "There is a difference of one goal, but just one is not enough because their away goal puts Arsenal in a very good position. "We have to fight and be positive if we are to qualify. Last season we made it to quarters, and our objective is to get there again. "There is always a first time [to win in England]. Tomorrow will be an elimination match, and we have never played against Arsenal in that before, so the opportunities are open for both teams." Ferreira rejected the suggestion Arsenal would be weaker without their talisman Fabregas. "Success always depends on the collective team, every player is part of that," he said. "Fabregas not playing will not change the way Arsenal face this match. "We can expect a very strong Arsenal tomorrow. "The match will probably be decided by small details - Arsenal are very good in dealing with these, but we will focus on our own strength." Ruben Micael made the most of Arsenal's costly mistake in the first leg, when stand-in keeper Lukasz Fabianski picked up a backpass from Sol Campbell, which Swedish referee Martin Hansson allowed to be taken quickly as Falcao swept the ball into an empty net. The Portugal midfielder said: "The goal counted, and it was not me who put the ball on the floor - the referee gave me the ball, put it down, he let me play. "That would not happen in Portuguese football, they would not let us play, so it is good they do that in the Champions League." Micael is expecting Arsenal to come out all guns blazing on Tuesday. He said: "Arsenal will start strongly, trying to score early. "However, we will also try to start well, going in the attack. "If we are to get to the next round, we need to be able to hold onto our result."
