Frank Lampard admits Chelsea's new signings need to step up their game.

There has been calls for Lampard to drop German duo Kai Havertz and Timo Werner after two consecutive Premier League defeats for the Blues.

And Lampard hopes those losses will put a rocket up his big money signings.

"We need to reflect on the two games we have lost points in, which is disappointing, but also know this is a long season. We have to bounce back; the players have to bounce back," Lampard told the club's official website.

"We're a young group, some players are new to this league, they need to wake up to what this is about right now, because games like the last two prove it."