The two sides are set to clash in a mouth-watering Premier League encounter on September 23. Mancini believes Arsene Wenger's men have a shot at the domestic title even though they haven't won a trophy in seven years.
According to the Italian's interview with ESPN, the Londoners have improved after losing key players across the summer.
Arsenal can compete for the title this season. They are better than last season, even if they lost some good players.
Maybe, because of that, there is less pressure on them this season.
They lost Van Persie and Song, but the players they have brought in have experience and quality.
Is Mancini displaying mind games so early in the campaign?
He'll be wary of an Arsenal side that is unbeaten in all competitions.
While City are yet to drop three points in the Premier League, the recent 3-2 Champions League loss to Real Madrid will be fresh in the memory.
Former Gunners' midfielder Samir Nasri is set to miss the match against his old club. The Frenchman is likely to sit out of the much-anticipated match amidst the reported return of Sergio Aguero (via The Daily Mail).
The influential forward is expected to start for a side that hasn't had any problem notching up 11 goals in his five-game absence.
Carlos Tevez, Edin Dzeko and Yaya Toure have been influential since the Argentinian hobbled off.
Toure faces a difficult task in shutting-down an Arsenal midfield that has played excellently this season; Toure is set to do battle with Abou Diaby in what could be a game-defining personal duel.
Mancini's praise doesn't hide the scale of such an important fixture. At this stage in the season any advantage will provide a boost to either side's title credentials.
If Arsenal are to be taken as seriously as Mancini suggests, they'll have to leave the Etihad with a win.