And after United failed to turn their technical superiority over Inter in to goals in the first leg, particularly in the first half, Mourinho senses that he once again can get the result needed at the home of the European champions.
'I've drawn 0-0 after the first leg in the Champions League before and gone through, so I'm very confident,' he said.
'A score draw will send us through and so our aim is to get a goal as early as we can at Old Trafford.
'If we can do that, and I'm sure we can, then we will have a fantastic chance to knock United out of the competition. We have a 50 per cent chance of going through to the next round.
'On the one hand, 0-0 is a difficult result for us because it means we can't lose at Old Trafford if we want to go through. But it's a difficult result for them because all we need is to score and make sure we draw. If we score, United have to win.
'We lacked any real intensity in the first half against United, but we realised in the second half that we could beat them and we improved a lot. So we can go to Manchester and be very hopeful of getting the result we need.'
Inter have been excellent on the road both domestically and in Europe this season, scoring more goals away from the San Siro in the Champions League.
And their leading striker, Zlatan Ibrahimovic, insists Inter will not be fazed by the task ahead of them in Manchester.
'We're very confident,' said Ibrahimovic. 'We want to win every game and we'll go to Manchester to try to win.
'United are a good team but we could even get a draw and go through.
'But I don't think that any team really goes out and plays for a draw. We'll be going there to win and then we'll just have to see how it turns out.
'Beating the European champions would be a real confidence boost for us and we believe we can do it.'
Meanwhile, Mourinho will be able to take his place in the Old Trafford dugout after Uefa declined to follow up on comments he made about the referee in the first leg of the tie.
Mourinho suggested Spanish official Luis Medina Cantalejo had been biased towards United. However, a Uefa spokesman said: 'No action will be taken.'