The Schwarzgelben supremo insists the Pole, who has been heavily linked with Bayern Munich, is not necessarily bound for the Signal Iduna Park exit door this summer
The Poland international's agent, Maik Barthel, claimed earlier this week his client had agreed to join Bayern Munich, with the Bundesliga champions said to have decided to meet the player's buy-out clause. However, both clubs denied this was the case.
Manchester United are also believed to be interested in Lewandowski, and this week boss Sir Alex Ferguson refused to rule out a summer move for the 24-year-old.
Indeed, while Watzke has now admitted to Aktuellen Sportstudio that Dortmund have ceded to a request from Lewandowski's advisers to discuss any "decent offers" received before May 15 for the forward, "that does not mean that Robert will definitely change [clubs]."
Bayern have already persuaded Dortmund playmaker Mario Gotze to swap Signal Iduna Park for the Allianz Arena this summer, with the Bavarians having agreed to meet the Germany international's €37 million (£31.5m) buy-out clause.