Bayer Leverkusen director Rudi Voller thinks Kai Havertz will join the 'world-class club'.
But Voller hopes he can hold onto the Germany international for a bit longer.
"I'm honest, I always have such a small hope that we can and will keep him here for another year," Germany legend Voller told Sky Sports on Wednesday.
"It doesn't change the fact that he's already a world-class player anyway, that's what he was before. Now the attention is even more on him.
"He will switch to an absolute world-class club at some point."