This is Barca's final and if we're not 2-0 up at half time, our Champions League dream is over, admits Alves

Dani Alves believes Barcelona have to be 2-0 by half time in their Champions League semi-final second leg tonight to stand any chance of pulling off a spectacular comeback against Bayern Munich. The Catalan giants trail 4-0 following last week’s humbling at the Allianz Arena, their hopes of making the final at Wembley on May 25 hanging by the thinnest of threads. 'We’ll give it everything. For us this match is like the final and we are obliged to give 200 per cent. 'If we score quickly it will help us because that will get Bayern thinking and nerves could set in.
'We are a team that increases its level of performance in our very worst moments and now we need to be at our very best. Bayern might be a big team — but so are we. And if the Germans arrive here relaxed in any way at all that will be a big error. Now is the moment for revenge.' A team containing Lionel Messi can not be written off, though, and coach Tito Vilanova insists no-one at Barcelona has given up hope. He said: 'We believe we can fight back, it’s our obligation and we’re convinced (it’s possible). 'We know that it will be very difficult, but we are Barca and we can never give up on a tie, especially when we have 90 minutes to play at home. 'We have to hold our heads high if we are eliminated. We cannot give up, we need to make our fans proud.' Defender Gerard Pique added: 'The only team that can overcome a 4-0 deficit to Bayern Munich is this club.' Messi was thoroughly overshadowed in the first leg when he appeared troubled by a hamstring problem, but Vilanova backed him to 'have things to say' tonight. He came off the bench and scored against Athletic Bilbao at the weekend. Vilanova said: 'The more in form he is the better our chances of getting to the final, but we can’t heap this kind pressure on him, we have to try to help him. A player as good as Messi, at this point in the competition, will have things to say in tomorrow’s match.' Bayern have won their last 10 games in all competitions and are now firm favourites to win the competition. They reached the final last term only to suffer a heart-breaking penalty shootout defeat to Chelsea in their own stadium and boss Jupp Heynckes thinks that disappointment has fuelled their desire this campaign. 'When you experience a final like we did against Chelsea, then you understand all the consequences,' Heynckes said. 'Some clubs give up, but everyone at Bayern reacted in a very positive way. We made changes, signed good players, modified some things, and strengthened the team spirit.' Source: Dailymail