Mancini has raised the possibility of not even being able to name a full complement of substitutes for Sunday's FA Cup third-round tie with Manchester United.
It is a rather bizarre position for the world's wealthiest club to find themselves in but has been arrived at following the refusal of Ivory Coast coach Francois Zahoui to allow Yaya and Kolo Toure to delay their departure for preparations ahead of the African Nations Cup.
That has compounded the difficulties caused by Gareth Barry's suspension and injuries to Mario Balotelli, Owen Hargreaves and, possibly, Samir Nasri.
It merely strengthens Mancini's fears he simply does not have the resources to be certain City will complete their championship quest without a major mishap.
"If we don't have the players it's tough for us," said the City boss.
"We are not United. We don't have 19 championships.
"United and Chelsea have won trophies for many years. So they are quiet. They understand that they can play without pressure. For us it's different.
"This could be the first championship for many years and we need to do everything we can to win it."
By doing everything, Mancini means not letting the strength of his squad be reduced significantly.
The problem for City's owners is not finding the cash, it is proving to UEFA they are serious about meeting the strict Financial Fair Play regulations that began this season and which the Blues are virtually certain to fail given the vast scale of their losses.
Only by reducing them dramatically will City's hierarchy hope to avoid punishment, which means Mancini may have to sell before be can buy.
To that end, the departure of Carlos Tevez cannot come soon enough, although any movement with AC Milan and Inter, who have also expressed an interest, is proving slow.
"It's better that we sell first," said Mancini. "Maybe then we can then take in other players.
"I said two months ago that we could have a big problem in January because we have to play big games without Yaya."
Indeed, Toure could miss up to five Premier League games, in addition to Sunday's FA Cup tie, the fourth round should City get through and the two-legged Carling Cup semi-final with Liverpool.
However, Mancini is also acutely aware that with Tevez remaining in Argentina, City have effectively been operating one striker down for the past three months.
"If we have strikers injured then we need to buy another," said Mancini.
"Because (Edin) Dzeko has a problem in his knee, at the moment I have one striker and two midfielders."
Instead of facing Sir Alex Ferguson's men, the Tours will be flying from Paris, where they are required for a team meeting on Saturday, to Abu Dhabi for a two-week training camp ahead of the tournament, jointly held in Gabon and Equatorial Guinea.
And evidently, Mancini has no faith in some of the back-up players outside his senior squad because he is contemplating the possibility of only naming six substitutes.
"For Sunday we have 17 players," he said. "I don't think we will have 18.
"Gareth is suspended, Mario is injured. Samir was better yesterday but I don't know."
The strange case of Owen Hargreaves offers little cause for optimism either as two starts in the Carling Cup and a substitute appearance in the Premier League win over Aston Villa have not given way to a more consistent presence in the City squad.
"Owen has worked with the team in the last two weeks without a problem," said Mancini.
"But it is clear that he is not Yaya at this moment.
"He needs to play and work. I hope he can be ready to play one game but it depends on him."
It leaves Mancini with just James Milner and Nigel de Jong available to face United from his pool of orthodox midfielders, although that could be supplemented by Pablo Zabaleta, or even Nasri should the former Arsenal man recover in time.