The Gabon striker is one of the most sought-after players in European football following prolific form for the Bundesliga side.
Express Sport understands Manchester City boss Pep Guardiola wants Aubameyang to replace Sergio Aguero.
10 facts about Pierre-Emerick Aubameyang
Tue, February 16, 2016
Express Sport brings you 10 facts about Premier League target Pierre-Emerick Aubameyang
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Express Sport brings you everything you need to know about Pierre-Emerick Aubameyang
While Manchester United have been credited with an interest in the past.
However, Aubameyang has stated his desire to play in La Liga and specifically for Real Madrid if the opportunity arose.
And Watzke has admitted Dortmund would have to think about selling the 27-year-old if a £68.5m (80m euros) bid came in.
Borussia Dortmund's Pierre-Emerick Aubameyang
"We can never guarantee that a player will stay with Borussia Dortmund forever, but our strength is to always find new solutions," he was quoted as saying by Kicker TV.
"Auba was our alternative to 'the world ending' after [Robert] Lewandowski's departure [to Bayern Munich].
"With an 80million [euro] offer, I would be thinking about [club president] Reinhard Rauball and [sporting director] Michael Zorc – if we had one [an offer], we would have to get together with Pierre-Emerick [to discuss it].
Pierre-Emerick Aubameyang has said he would like to play for Real Madrid
"We always have to differentiate between situations where there is such an offer, but we have no pressure… I would prefer it if no offer came.
"[He] is definitely good enough to go to an even bigger club.
"There are only a few, but I'm glad to read that it's a good idea to go to Barcelona."