The two Manchester clubs go head-to-head on Sunday in the traditioinal curtain-raiser between the previous season's domestic winners - but despite spending heavily in recent year, Mancini believes they are still behind Sir Alex Ferguson’s team.
Manchester United won the Premier League title last season, finishing nine points ahead of Mancini’s men, though Manchester City won the FA Cup, indicating that the gap is closing.
“Manchester United at the moment are on top,” Mancini told reporters.
“They are a strong team, they won the Barclays Premier League and have bought four or five good players.
“I think we are very close but at the moment they are above us.”
Manchester City will start the game without talismanic striker, Carlos Tevez who is yet to return from holiday, whilst new record signing Sergio Aguero is not fit enough to start, though he is expected to make the bench.