Bayer Leverkusen have disclosed to Chelsea they need to finish an arrangement for Kai Havertz by August 28.
Havertz is quick to join the Blues, yet the two clubs have failed to agree a fee.
Bayer are requesting for £90million, while Chelsea are willing to pay £70million.
Leverkusen’s players will report for preseason next Friday and need Havertz future to be sifted through by at that point.
The Bundesliga side saw their season finished after a 2-1 loss to Inter Milan in the Europa League quarter-final and are currently set for new talks with Havertz.
The club’s CEO Fernando Carro said last week: “It was always clear that we will have talks once the Europa League season concluded.
“Kai has voiced his desire to make the next step. At the moment, I can’t say whether this will work out in the near future or not.”