The arrivals of Carlos Tevez from United, Emmanuel Adebayor and Kolo Toure from Arsenal, Roque Santa Cruz from Blackburn and Gareth Barry from Aston Villa should certainly see City improve in the new Premier League season starting this weekend.
However, it is not the signings themselves that have got under the skin of Manchester United boss Alex Ferguson, who is plotting a title defence without world player of the year Cristiano Ronaldo, sold to Real Madrid, as well as Tevez.
What really rankles at Old Trafford is City's assertion that they are about to challenge for a place in the top four, and ultimately United's position as the biggest club in England.
City tweaked United's nose when a huge banner was erected in the city centre showing Tevez in a City shirt with the slogan "Welcome to Manchester" underneath his photograph - a cheeky reference to the fact that United's home of Old Trafford is actually situated in Salford, outside Manchester city limits.
"They are a small club with a small mentality," responded Ferguson. "All they can talk about is Manchester United."
He continued: "It will not be easy for City this season, and for me they don't even come into the top four equation. For all the buying they have done, Mark Hughes still has to find the right balance, and what's he got - 10 strikers?"
He told reporters recently: "I remember the pressure Alex Ferguson was under when I was a United player and he went four years before winning the FA Cup. The first trophy is the hardest. Then success becomes a natural thing because you have experienced how to achieve it.
"I know the pressure I am under. The owners want to take this club into the top four and Champions League very quickly."
If free signing Michael Owen rediscovers his old scoring touch alongside Wayne Rooney and Dimitar Berbatov, the effect of Ronaldo's absence and his goal contribution will be diluted.
