Frank Lampard has cautioned Chelsea not to get carried away with their flying start to the season.
Blues fans will recall the collapse two years ago after winning their first five league games in a blaze of 21 goals under Carlo Ancelotti.
"It's a nice patch but we've had nice patches in the past that have fizzled out," said Lampard.
"There is a very important period coming up,' said Ivanovic. 'We have some very tough games."