The 24-year-old Bosnia striker is one of the Bundesliga's most prolific scorers and City are reported to be in negotiations to sign him from VfL Wolfsburg once the transfer window opens on Saturday.
"We have the chance to win the league this year and the decisive factor could be Edin Dzeko," Italian Mancini said in the Daily Mail. "This player can decide titles and that is why we want him."
City, who are level on points with Manchester United at the top of the table, albeit having played two more games, have relied heavily on the goals of Carlos Tevez.
With Emmanuel Adebayor and Roque Santa Cruz both out of favour with Mancini and Mario Balotelli yet to settle despite his hat-trick in the 4-0 win over Aston Villa on Tuesday, Dzeko's goalscoring record looks enticing.
Dzeko was Bundesliga top-scorer with 22 goals last season and second topscorer the season in 2008/09 with 26, when Wolfsburg won the title.
He has scored 10 league goals in the first half of this season, even though Wolfsburg are struggling in 13th place.
Wolfsburg's English manager Steve McClaren said recently that it could be hard for the club to keep hold of Dzeko.
"We hope that Edin stays because he is a world class striker, but we are in the business of football and nothing is 100 percent certain," he said. "We will have to see what happens."
Wolfsburg have declined to comment on the speculation surrounding the player.
