David Silva says Manchester City must not be complacent facing FA Cup opponents Manchester United tomorrow.

Silva believes United will be motivated by the 6-1 humiliation they suffered at Old Trafford earlier in the season.

The Spanish sensation said: "In some ways if they concentrate on that 6-1 defeat by us it could be a negative, but at the same time it could provide an extra motivation for them in trying to kick us out of the FA Cup.

"Manchester United are a dangerous team because of the inconsistency in their form.

"One minute they are suffering against teams they feel they should beat like Blackburn, and then the next minute they are beating sides like Chelsea. The 6-1 win at Old Trafford was magical. It was an incredible day, but it is not a scoreline I feel will ever be repeated.

"We will need to control the midfield and win the battle for possession."