Barcelona hero Ronaldinho believes Manchester United can upset them in tonight's Champions League clash.

Ronaldinho believes the first goal will be crucial - and that if United can get it home fans will start to get nervous.

The Brazilian superstar, who spent five seasons with Barca and helped them win the Champions League in 2006, told the Daily Star: “The truth is that Barcelona should have finished the game in Manchester - but at just 1-0 Manchester United will still believe that are in this tie.

“With the way that Barcelona have been playing and the amount of goals they have been scoring, I do expect them to progress.

“I see them even winning comfortably in Barcelona. It will all be on the first goal.

“If Barcelona score it then it will be a long evening for Manchester United.

“But if they (United) can score the first goal then it's going to make the stadium nervous - and you never know what can happen then."