The Brazilian admits that Carlo Ancelotti's Blues are the top side in England at the moment - but they are not unstoppable.
Robinho declared: "We must drown their midfield, open the scoring - and stop Didier Drogba.
"It is not an easy game for us but given the spirit in our squad this week, I believe the Blues will suffer in Manchester.
"It's the basics for us. We must score goals - without them we don't win matches.
"Drogba is one of the best strikers in the world and Nicolas Anelka is having some big moments too. We are working on a system to stop them - but our defence must avoid any costly errors.