The England international is a long-term target for Manchester United, who tried and failed to prise him away from the Westfalenstadion last year, and they are expected to reignite their interest in the attacker ahead of the 2021-22 season.
Furthermore, Dortmund are facing the prospect of losing some of their biggest names if they fail to qualify for the Champions League, and Watzke has not ruled out an exit for Sancho if the right price is met.
Speaking to Goal, the Dortmund chief said: "I'm not getting involved in probabilities, it's no good. Jadon Sancho has been with us much longer than Erling Haaland. We'll have to speak to Jadon too.
"If there is an exceptional offer we will discuss it with the player and the agent, as always. Nonetheless, I am very sure that the transfer market will only run to a very limited extent this summer.
"Especially at the really big clubs you can see what kind of wounds coronavirus has inflicted, and they are not small ones that heal within two weeks."
Sancho would have hoped to feature for the Black and Yellow against his former club Manchester City in Tuesday's Champions League battle, but he is expected to miss out with a thigh injury. body check tags ::