Fernando is convinced he joined the right Manchester club.
The Brazilian midfielder signed for Manchester City for 12 million pounds in the summer -- but only after he was scouted extensively by Manchester United during David Moyes' reign.
Premier League champions City are certain to go into Sunday's meeting at the Etihad Stadium ahead of Louis van Gaal's team, and Fernando said: "We know that United are going through a difficult time recently but that can happen to any team. They have good players.
Sam Allardyce believes on-loan midfielder Alex Song will be a "Yaya Toure-type signing" for West Ham this season.
Song swapped the Nou Camp for Upton Park when he moved from Barcelona in August and the 26-year-old has helped lift the Hammers to fourth in the Barclays Premier League table.
West Ham's strong start will be given a rigorous examination when they host defending champions Manchester City on Saturday and when asked about his opponents' world-class stars, Allardyce said: "We've got that type...