The long-time Barclays Premier League leaders have fallen five points behind rivals Manchester United with just seven games remaining following a series of costly results in March, and could be trailing by eight by the time they kick off at Arsenal on Sunday if United beat QPR earlier in the day.
"If we lose against Arsenal and they beat QPR - yes," said Mancini, when asked if the race would be over should that happen.
But the Italian insists he is not thinking that way as he prepares for the crucial trip to the Emirates Stadium.
City, who led the table by two points at the start of last month, have come unstuck in recent weeks after a defeat at Swansea and draws against Stoke and Sunderland.
Mancini said: "I think always positive, I can't think this.
"Against Sunderland we didn't play very well, for me we were so flat in the first half. But we shot 25 times on goal, we had 65% ball possession. Sunderland shot three times at goal and scored three goals.
"We did some mistakes defensively but we were unlucky.
"But now we can say nothing, we can't think about Sunderland. We should think positive for the next seven games.
"I think it may be more difficult, but it is my opinion that this championship is not finished."
Source: PA
Source: PA