Dembele has skipped training sessions as he attempts to force through a move to Barca.
Watzke believes the Frenchman isn't acting alone, telling Sky Deutschland: "Ousmane does not mock us, he just refuses to work. It is a new quality. And we must speak of the role of the glorious Barca in this decision.
"On Wednesday we met with the leaders of Barcelona. Our positions were very far from one another. Then, on Thursday, he did not come to the training. The timing of these events is very curious. You do not think a 20-year-old would refuse to go to practice without his new club liking it?"