Ilkay Gundogan has warned his Manchester City team-mates of Kai Havertz's quality with the midfielder suggesting that his compatriot is already better than Michael Ballack ever was.
Havertz is a key target for Chelsea, who have already signed Timo Werner this summer.
Werner was bought for £53million while talks with Bayer Leverkusen over a £75m move for Havertz are ongoing.
Gundogan plays with Havertz and Werner for Germany and is aware of how good the pair can be at full flow.
Havertz, according to the City midfielder, is even better than former Chelsea and Germany international Ballack was in his pomp.