The Premier League champions trail rivals Manchester United by 15 points and the Italian warns that he will make decisions about next season's squad based on the remaining matches
The champions have found the defence of their 2011-12 triumph difficult, with Sir Alex Ferguson's side racing 15 points clear at the top of the table to leave the Italian manager's future at the Etihad Stadium uncertain.
But, despite the disappointment of City trailing their bitter rivals, Mancini has called on his squad to prove that they will be up to the task next season by finishing this campaign as strongly as possible.
"The games we have from now until the end of the season are very important," he told reporters. "At this moment we don't know what players we can buy at the end of the season and which players can leave.
"Some players will want to leave because they don't play and they will want more chances to play. Maybe that will happen. These are decisions for the next 11 games, yes."
City have a game in hand over United but must win at Aston Villa on Monday night to close to within 12 points of the Red Devils once again. However, Mancini still feels that the leaders could slip up - just as they did last season.
"It is difficult to see where United will drop points but last year no-one thought they would lose the game against Wigan or other games," he continued.
"When you get to the last seven, eight or nine games of the season, it becomes harder for everyone because teams are playing for relegation, the Europa League and the Champions League.
"Every game becomes difficult then, especially when you are playing every three days. United have a lot of games - important games - in the Champions League and FA Cup. We hope they can lose points, but we don't know when and we don't know where."