Despite conceding that a number of clubs have a genuine chance of lifting the trophy next May, Dzeko believes that it is Jose Mourinho's side who are the biggest threat to City's hopes of winning a third title in four years.
"It will be difficult, but I'm an optimist," the 28-year-old is quoted as saying by The Mirror. "As with every season, there are several teams that will battle for the title of champions in England.
"This season Chelsea might be the most serious challenger, but we mustn't ignore Liverpool, Tottenham, Arsenal, or [Manchester] United, who will certainly be much stronger than last year.
"After all, everyone has got stronger, and everyone wants to be first."
Dzeko recently declared himself delighted with the four-year contract he signed last month.