Former Manchester United assistant Mike Phelan has backed the Premier League champions to derail Manchester City's title charge this evening.
In an interview with talkSPORT, the 51-year-old has warned against writing off his old club, suggesting that form counts for nothing when it comes to the Manchester derby.
David Moyes's Red Devils side are currently 12 points behind tonight's opponents, but will go into tonight's clash at Old Trafford high on confidence, following back-to-back victories against Olympiakos and West Ham at the weekend.
Manuel Pellegrini's side meanwhile still have sights firmly set on the domestic crown, and will take belief from their 4-1 victory over Manchester United at the Etihad Stadium earlier in the season.
However, Phelan is adamant that Manchester United can upset the apple cart on Tuesday evening, despite the fact that on the whole, the club has endured a miserable 2013/14 campaign so far.
"Players go into a big game in the best frame of mind. This is where they earn their corn and it means so much to the city of Manchester.
"You would expect United to be really up for this because they have a lot to prove from what has been a disappointing season."
Phelan added: "I would never rule out Manchester United. They have still got very, very talented players. They have just lost their way a little bit, but the talent is there, the quality is there. It is just making sure the heads are on right when it comes to the big games.
"I would never rule United out in a big game at Old Trafford. They can upset any team. It depends on his selection and tactics but I would still favour Man United to upset the apple cart tonight."
Moyes will certainly be hoping that his Manchester United players' heads are right as they prepare to host Manchester City in the Premier League this evening.