Kai Havertz completed a medical with Chelsea in London on Sunday, reports have claimed.
The Blues have agreed to pay an initial £72m to Bayer Leverkusen, with an additional £18m of add-ons included.
The 21-year-old will sign a five-year contact with his new club.
And Bild’s head of football writer Christian Falk has confirmed Havertz passed a medical in England before linking up with the German national team on Monday.
He will become Chelsea’s club-record signing and the most expensive German player of all-time.
Chelsea will have to register Havertz by Thursday if he plays for Germany to be able to apply for an exemption so he won’t have to quarantine upon his arrival in the UK.
If they don’t Havertz risks missing the start of the Premier League season.