Watzke insists both clubs should be aware that he is not for sale.
"I clearly hope that Erling Haaland will play for us next year," he told BILD.
In April, the player's father and his agent, Mino Raiola, met with both clubs to find out first-hand the intention of the two, yet Watzke remains firm on his stance.
"I'm totally relaxed. Nobody believed us with Jadon Sancho last summer until the deadline, and today he's still with us," Watzke said.
"Either you have a squad where you sign a player and let him go, or you don't. We can live with it, and feel good, because we know the contractual situation, which helps us a lot," he said.