Roberto Mancini has declared that Manchester City came "very close" to buying Robin van Persie from Arsenal and feels the Manchester United striker could make the difference in the title race.
Sir Alex Ferguson tied up a £24 million deal for Van Persie in August but Mancini revealed City almost signed the Dutchman months earlier.
And he lamented City's inability to bring in Van Persie, saying that it was an opportunity to become even stronger and give them more options in attack.
"We were very close. He took his decision but three or four months before we were there," Mancini said, making a gesture with his hand to show how the small distance between the striker and City was.
City won the Premier League title on goal difference from United last season but now Ferguson's side have a seven-point advantage, aided by Van Persie's Manchester derby winner at the Etihad Stadium on December 9.
The 29-year-old has scored 14 Premier League goals, which have been worth 19 points to United and Mancini believes he has swing the balance of power United's way.
He added: "It is clear he has changed the situation. In this moment, he is the difference. Last year we were the team that scored the most goals in the Premier League and I am very happy [with my forwards]. But we wanted Van Persie because he is totally different from our other strikers. When you can improve your team with top players it is important [to do it]. With Van Persie we could also play with three strikers sometimes. But now we can do nothing."
And Mancini admitted he expects more from his summer signings, with the exception of Matija Nastasic, who has established himself at the centre of the City defence. Maicon and Jack Rodwell have been injured for much of their City careers, while Javi Garcia has also spent a spell on the sidelines and Scott Sinclair has barely featured.
Mancini said: "These players can do better. Garcia started very well, he played the first game against Stoke and then he got an injury and was out for 40 days. Now he has started to play and he can be important.
"Scott is my fault because I didn't get him a big chance to play. He's fantastic because he always works hard and when he has the chance he plays 100%."
Mancini ruled out letting Joleon Lescott leave because he is short of fit players and Kolo Toure will be absent for at least a month because of the African Cup of Nations.
He explained: "I can understand that Joleon wants to play because he is an England player and it is difficult for him. But we can't sell Joleon because we don't have other players."