City manager Mancini reckons the next two months will prove decisive in determining the outcome of the Premier League title race.
The Italian saw his side’s lead at the top of the table cut to just two points by Manchester United after the reigning English champions beat Wolves 4-1 on Saturday.
But City, who have a game in hand over their local rivals, will again move five points clear if they win at Stamford Bridge.
And victory in west London would also leave City a huge 13 points in front of Chelsea, a team expected to be one of their main title rivals this season.
That would at least provide some consolation following their elimination from European football’s premier club competition at the group stage.
Victory over Bayern Munich wasn’t enough to take City into the knock-out phase and with a match against Arsenal six days after the Chelsea clash, Mancini knows they have a great chance to strengthen their Premier League title claims.
“I think it is good to play this game, it is an important game against a top team,” Mancini said.
“Up to now in the Premier League we’ve done well, but the season is long.
“Now we face two difficult games against Chelsea and Arsenal. Then after that we have to play every three days. The next two months will be important for us.
“Over the last two weeks Chelsea have improved and they are still a fantastic team. It will be a good game between two strong teams.
“We go there to win,” said Mancini, bidding to become the first City manager to take the English title since Joe Mercer’s team won the old First Division trophy in 1968.
While City bowed out of the Champions League, Chelsea remained involved following a 3-0 win over Valencia.
That victory lifted the mood of the London club although Chelsea manager Andre Villas-Boas admitted defeat by City could spell the end of his side’s title hopes.
“There’s no quitting, and there will be no quitting of belief. But 13 points would be a massive gap again.”
However, the Portuguese boss remains in bullish mood and, having described the Valencia win as a “slap in the face” to those who had questioned Chelsea’s prospects this season, he returned to the theme ahead of the City game.
“It’s fair for you guys to admit that the media darlings of the press are blue collar and not Chelsea,” he told reporters.
“We were unfairly treated a couple of times, and fairly by yourselves in the beginning. It’s a love and hate relationship.”
He added: “A lot of things that were said, most of the things, were wrong.
“One day I will open the doors of training for you guys (the press) for a couple of days and you will see the players have the talent and ability and want to compete. That’s what we hold on to during extreme criticism.”
Villas-Boas has also been keen to dampen down any suggestion his dressing room has been divided despite growing uncertainty about the future of a number of players including Alex, Nicolas Anelka, Frank Lampard and Didier Drogba.
Lampard was left on the bench for the Valencia game but the manager denies the England midfielder is poised to leave for LA Galaxy.
“I have no idea,” he said when asked about reports linking the player to the US club best known for signing former England captain David Beckham. “There is nothing from our side.”