Alex Ferguson wants Manchester United away goal

Manchester United boss Sir Alex Ferguson believes his side must score when they face Roma in their Champions League tie at the Stadio Olympico.

Roma knocked out Lyon in the previous round, despite the French club holding them to a goalless draw in Italy.

"We need to score. A goalless draw is a dangerous scoreline," said Ferguson, whose side face Roma in European competition for the first time.

"Lyon were the better team in Rome but you saw what happened in France."

Lyon appeared to have done the hard work by claiming a goalless draw in the Italian capital but on home soil they slipped to a 2-0 defeat.

Despite scoring 74 goals in 31 Premiership games this season, United have not been at their attacking best in the Champions League this season.

Striker Wayne Rooney is yet to score in a Champions League game since his memorable hat-trick on debut against Fenerbahce in September 2004.

Portugal winger Cristiano Ronaldo has not scored at all for United on the biggest European stage.

"I don't know why the pair of them have not scored in the Champions League," added Ferguson.

"We have not scored a lot of goals in Europe over the last two years at all, which is obviously a factor.

"Maybe it is just a case of them adapting to European football because they are both young players. But I don't have an issue with either of them.

"Wayne's contribution has been very good, while I believe Cristiano is the best player in the world just now."

He said: "We are playing well and the team is scoring goals so it doesn't concern me.

"We are winning all our games. A lot of people have been scoring goals and the defence have been brilliant as well."

Meanwhile, Roma defender Christian Panucci has warned Ronaldo he can expect no favours from the referee.

Panucci told the Daily Mail: "Ronaldo's class is unquestionable but he exaggerates his falls and we won't fall for tricks.

"I believe he abuses his dribbling talents and a lot will depend on the referee but in Roma, Ronaldo will not be daring enough to do it."

Brazilian striker Mancini added: "I've watched Premier League matches and Ronaldo is protected by referees. I don't think he will be on Wednesday."