City are coming to Old Trafford with a confident arrogance about them, certain they can close the gap at the top of the table with Wolves beating their bitter enemy last week.
Nani, though, insists that result was just a blip and is desperate to get back on track against Roberto Mancini's side.
He told The Sun: "The defeat at Wolves was an accident. It left pain in the dressing room but one week later we have the chance to return joy to our fans.
"A win over City is an obligation. To beat them will put a big distance between us in the title race and also mean we have taken four points off them this season.
"I've always been optimistic and insist we are favourites to win the Premier League."