Chelsea midfielder Mateo Kovacic has hailed the form of Kai Havertz ahead of today's clash with Manchester City.

Kovacic believes Chelsea are starting to see the best of Havertz now that the German has adapted to a new country and a new league.

"I'm very glad for him because I saw from the first training what kind of quality Kai has," said the 27-year-old to chelseafc.com. "It was a tough start for him, which is normal because he's young coming to a new country.

"He just changed in the last half a year and has adapted now very well to the Premier League. He knows how to play in such a physical league, he showed great character and that's what true champions do.

"They perform every week and he's doing that now. He's playing class football because he's a class player."