Manchester United boss Sir Alex Ferguson remains wary of Manchester City.

Robin van Persie's presence has given the Red Devils a healthy advantage over Manchester City, who could yet be opponents in the FA Cup as the two clubs continue to compete for major honours.

"They are our danger," said Ferguson.

"A year ago I made the point that we will be playing them in big games all the time now, whether it is the FA Cup, the Community Shield or challenging for the league.

"We accept the challenge. We are not afraid of it.

"Look at the challenge Sir Matt (Busby) had after losing his team in 1958. It is the kind of challenge Manchester United are good at."