The Scot expects City to be a thorn in United’s flesh this season and Fergie acknowledges that United will have to play at their best if they are to reach their 20th Premier League title, City have emerged as realistic challengers for major honours since Sheikh Mansour's takeover of the club and heavily investing in the team.
He said: "There was a period not so long ago when City were actually in the second division and they were never a thorn in our flesh.
The Manchester United manager also went on to add; "Whereas every year in the past we've had to contend with Arsenal, Chelsea or Liverpool.
"But winning a trophy does you a power of good. I don't think there's any doubt about that. It takes the pressure off the manager and gives confidence to the players.
"We've experienced it ourselves over the years and we expect City to be challengers next season.
"But nothing changes. One of the teams will always be a thorn in our flesh, whether we like it or not - possibly all four of them."
Ferguson also believes that Liverpool, who have endured a difficult time of late, will be back to their best under Kenny Dalglish this season.
He added: "Liverpool went off the radar for a bit. They are now back on it.
"Long term you know they are going to there."
Ferguson has also reiterated his desire to maintain his position in the United hot seat and has played down speculation that he could retire soon, when speaking about if he looking for retire soon he added; "Absolutely not,"
"Not at all. I'm not even thinking about it. You just have to keep going.
"The challenge, whether it's with young players or old players, is that you have to do something. There's always that expectation at this club."
