The winger has already been verbally abused at a friendly in Oxford after being singled out following England's World Cup exit to Portugal and more of the same can be expected at Charlton and Watford this week as Manchester United embark on their first away days of the new Premiership season.

So far, the 21-year-old has shown little sign of being affected by the barracking, scoring twice at Oxford, then another in United's friendly win over Sevilla when he received huge applause from the home fans.

"We don't need to shield Cristiano," said Ferguson.

"I don't think fans are that vicious in terms of needing security and safety.

"They may boo. That is no problem. Cristiano is mentally strong, so they can boo as long as they like.

"These situations are nothing new to us. We had it with Eric Cantona and David Beckham. They were burning effigies of David at West Ham immediately after the 1998 World Cup.

"We navigated it and so did David and we will do the same again."

Even though Wayne Rooney has pleaded for fans to lay off his teammate, insisting he bears no grudges for Ronaldo's behaviour as he was sent off in Gelsenkirchen, it seems certain there will be an adverse reaction to the Portugal star.