Chelsea signing Kai Havertz has admitted the intensity in the Premier League is "very exhausting" compared to the relative calm of the Bundesliga.
The 21-year-old joined the Blues from Bayer Leverkusen last month, and has made five appearances for Frank Lampard's side.
Short of match fitness, Havertz looked off the pace in his Premier League debut at Brighton but scored a hat-trick as Chelsea sealed a 6-0 victory against Barnsley in the third round of the Carabao Cup.
The Chelsea newcomer accepts he will need a period to adapt to top flight football in England, but insists there is plenty more to come.
"It was difficult for me, especially because the Premier League is a completely different league," Havertz told Chelsea's official website. "It's more intense and I noticed that in the first few games.
"The intensity in the duels and the runs is much higher. It's a completely different league and the games are very exhausting.
"The Bundesliga isn't worse but I noticed differences. It seems to me like there aren't any average or bad players here - everybody is at a very high level."
