They cut the gap to leaders Manchester United to 12 points as Carlos Tevez scored the only goal against Aston Villa on Monday night but Mancini knows his side face an uphill battle to reel in Sir Alex Ferguson's men.
The Italian said: "It is difficult because we have 30 points to play for and we need to try to win. At the end, we will see what happens. In football everything can happen right up to the last second. We probably need to win all 10 matches that are left. We need to win all the matches."
He added: "If they (United) lose three or four or five games.....it is difficult because they are too strong for this.
"When you have to win always, it is difficult to win every game. But last year we did this. Why can't we do it this year?"
Villa remain in the bottom three and manager Paul Lambert admitted a mistake by defender Ciaran Clark proved crucial in the build-up to Tevez's decider.
Lambert said: "I thought we were well in the game. The goal is a mistake. I wouldn't have minded if someone had put one in the top corner with a bit of skill.
"But it's a mistake by us. It is easy to be critical of Ciaran. The lad has been excellent all season. He will learn from it, he won't make the same mistake again."
Midfielder Fabian Delph will be suspended for the next two games against Reading and QPR after collecting his 10th booking of the season for handball.
Lambert said: "He's playing extremely well, really well. You are pressing forward, to try and get a goal back and things like that happen."
- Sports & Recreation
- Carlos Tevez
- Sir Alex Ferguson
- Aston Villa
- Manchester United