Manchester United"s Rafael fears that they could be exposed by champions Manchester City ahead of the derby clash on Sunday.
Vote for Rafael in the 2012 Samba Gold Trophy
The Red Devils have had a leaky defence this season, having conceded first in 15 of the last 23 games and Rafael believes they cannot afford to do the same against the Citizens.
“If we defend like we have done in some games we will be in real trouble against a team like City.
“That"s 100% sure. I don"t know why we have had problems defending this season. If we work hard in training I"m sure we can learn to defend better.
“In the Premier League Manchester City are doing very well – they just seem to keep going and going. But we just need to concentrate on ourselves.
“It is a big game for us and we need to play at our best level. They have a very good attack with some quality strikers. This will be our biggest test of the season.
“They have two Argentina strikers [Carlos Tevez and Sergio Agüero] and I am from Brazil so that increases the rivalry for me."
Rafael is also one of our 30 nominees for the 2012 Samba Gold Trophy which recognises the best performing Brazilian playing in Europe.
