Bayer Leverkusen chief Rudi Voller has fired a warning at Chelsea over Kai Havertz's asking price.
Voller is adamant Havertz will only leave for top price - with a mooted €80m price-tag believed to have been slapped on the midfielder.
"It is carved in stone. There is no new attitude," he told Kicker.
"There will be no corona bonus. Regardless of who the player is, this is a special transfer window."
Havertz is training with Bayer ahead of next week's Europa League clash with Rangers.
