Chelsea have made a blistering start to the season with four wins from as many matches, scoring 15 goals in the process.
New signing Diego Costa has already bagged seven league goals - four more than any other player - and they sit five points clear of champions City ahead of the Etihad Stadium clash.
And despite the early nature of the season, Silva is fully aware of the importance of avoiding defeat against Jose Mourinho's in-form men.
"It is a very important game," Silva told a news conference on Thursday.
"They are first in the [Premier] league and have more points than us. We can't lose on Sunday and let that gap get any bigger. So it is a very important game.
"It is early in this stage, it's still a long way to go in the Premier League and anything can happen.
"[But] yes, we need to win on Sunday because otherwise the gap will start to get too big.
"I think Chelsea have made fantastic signings this year... but we are a strong team. We've got a big team so as always we've got to go out there and win the game."
Silva was also unconcerned at City's start to the season - which has seen them take seven points from four matches.
And he said last year proved they can start slowly and still win the Premier League title.
"Loads of players have started late because of the World Cup and I think it takes time to be 100 percent - which we are still not," he added.
"Last year we started the same and we ended up winning the title. So hopefully this year it will be the same - a slow start and we end up winning."
