Bayer Leverkusen sporting director Rudi Voller claims that they can only sell Chelsea target Kai Havertz if "certain conditions" are met.
Voller claims an exit will only happen this summer if Leverkusen's expectations are met in full. Frank Lampard hopes to seal a £70million deal for the German international
"No decision has been made yet. I'd like to repeat myself by emphasising that we're talking about a wonderful footballer,' he told German publication Kicker.
"There is nothing new in this regard. We have a clear and mutual agreement with him and his representatives that he can only leave under certain conditions."
Havertz was on the scoresheet during the last-eight clash against Inter Milan in Dusseldorf on Monday night, but goals from Nicolo Barella and Romelu Lukaku condemned Peter Bosz's side to an exit from European football's secondary club competition.