Sir Alex Ferguson says

John O’Shea’s first half strike in last week’s Champions League semi-final first leg at Old Trafford means a win, draw or even a defeat by a one-goal margin against the Gunners would see United through to the final in Rome later this month.

But Sir Alex insists his players will not be just going to the Emirates to defend their lead - they will instead be aiming to get themselves on the scoresheet, especially as one away goal for the Reds would leave Arsenal needing at least three.

“We must go there with the intent of trying to score,” the boss told reporters at his pre-match press conference. “It's important that we have a goal threat. We certainly have the ability to score and hopefully we can as it would put us in a very strong position.

“Saying that, I still expect it to be a very close game and one that's very difficult to call. It could even go to extra-time or penalties. That's why I keep stressing the importance of us scoring a goal.”

While highlighting the need to attack, the United boss is also acutely aware of the importance of maintaining a solid backline with Arsene Wenger's men at least needing to score once in order to keep their Champions League dreams alive.

“We expect Arsenal to attack us. We've played them enough times in the past to know that's what they do so we therefore need a similar kind of performance to the one we produced in Porto with that same level of concentration,” he insisted. “And we're capable of producing that.

“I think they’ll change their system from last week. The fact that [Robin] van Persie trained on Monday is an indication he’ll be ready and therefore I expect to go 4-4-2.

“The history and nature of both clubs suggests it will be quite an open game and I don’t think people will be disappointed," he added.

“Hopefully we can get the result we want. There has been a good consistency about the team in the last couple of years in Europe and I hope that stands strong on Tuesday.”