Jose Mourinho's men have made a dream start to the campaign, winning six of their opening seven league games to pull clear of last season's champions City.
However, Silva feels the unpredictability of the Premier League ensures the current leaders will encounter problems at some stage.
"Chelsea have made great transfers, they have a great team, a great squad," Silva said after playing for Spain in their 4-0 win over Luxembourg in Euro 2016 qualifying on Sunday.
"But it doesn't mean things are going to be easy, especially in England."
One of Chelsea's close-season signings, Diego Costa, finally ended his goalscoring drought at international level with a goal in Spain's win.
Silva said the Brazil-born striker, who has enjoyed immediate success in the Premier League, had simply been unlucky in previous outings for Spain.
"He wanted to score but he was unlucky. He has scored today and we hope that he can keep the goals coming," Silva said.
City return to Premier League action with a clash against Tottenham on Saturday.
