The Premier League title favourites saw a 20-game unbeaten streak in all competitions ended when Branislav Ivanovic's 32nd-minute goal separated the two sides at the final whistle.
The defeat, City's first at home this season, saw them drop two points behind league leaders Arsenal but defender Zabaleta says it is not time for the 2012 champions to start licking their wounds.
"We were a little bit frustrated by the result but this is football. Sometimes you can lose games," he said.
"We can learn from mistakes and we see how difficult the Premier League is at the moment. Every game is very difficult.
"We need to keep calm. I think the manager is clever enough to work during the week and show to us on video what we did wrong and try to do well next game.
"We know we are only two points behind Arsenal and there is still a long way to go. We have got 14 games more to the end of the season. We need to be positive.
"We still have a chance in four competitions. We have important games coming up in February. We need to have a good rest now and be ready for Saturday. That is going to be another tough game, Norwich away."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball