Bayer Leverkusen told Chelsea that they should complete a deal for Kai Havertz before August 28.
Havertz wants to join the Blues, but both clubs have not agreed on a price.
Chelsea said it’s willing to pay £70million, but Bayer is insisting on £90million.
Players of Leverkusen club will be reporting for preseason next Friday and want the future of Havertz to be sorted out before then.
The Bundesliga saw the end of their season after Inter Milan defeated them by 2-1 in the Europa League quarter-final.
Fernando Carro, the club’s CEO said last week: “it was obvious that after the Europa League season has concluded, we will have talks.
“Kai has declared 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.”