Mancini's side tackle the champions at Eastlands on Saturday with a patched-up side containing just three fully-fit senior defenders.
It is hardly the backdrop he wanted heading into one of the key games of the campaign, and not one that was anticipated when City were spending in excess of £100million this summer.
However, according to Mancini, the result will not have an affect on where the championship ends up this season.
"Chelsea are the best team in the Premier League at the moment," he said.
"They are probably going to win the Premier League title easily.
"They are a strong team, who have been playing together for many years.
"They have a fantastic manager and they have worked to reach this situation."
Chelsea certainly could not have started the season in better form and have registered a perfect 15 points from their opening five games, scoring a hatful of goals in the process.
Now City must try to keep them out with a side that has been decimated.
Micah Richards has definitely been ruled out with a hamstring strain, so with Pablo Zabaleta earmarked for the right-back role, Mancini only has youngster Dedryck Boyata, plus midfielders Gareth Barry and James Milner available to fill the left-back slot if neither Joleon Lescott or Jerome Boateng are deemed to be fit enough.
Lescott has been troubled by a groin injury that has kept him out of City's last three games, while Boateng has not featured at all since his summer move from Hamburg after aggravating a knee injury when he was accidentally struck by a in-flight meal trolley.
"Joleon has worked with us for one day. He is not ready to play 90 minutes," said Mancini. "Jerome has been working with us for one week. He is not ready to play 100%.
"I do not know what I am going to do just yet. I will speak with Joleon and Jerome, but if they are not available I am not sure. Maybe Boyata, but I am not sure."
Emmanuel Adebayor should be fit enough to make the bench after a recent spell on the sidelines with a dead leg.
However, with Shaun Wright-Phillips joining Aleksander Kolarov and Mario Balotelli on the sidelines with a knee injury, Mancini cannot believe his squad has so rapidly been torn apart.
"I am disappointed we have all these injuries at the moment," he said. "I only have 11 players who are 100% fit."