The 53-year-old stated the Bundesliga champions will not sacrifice their financial model in favour of an overseas benefactor akin to Sheikh Mansour at Premier League champions City.
And Watzke warned Uefa's new Financial Fair Play model is doomed to failure unless they investigate the sponsorship deals clubs are making as they attempt to avoid new financial regulations.
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"No tycoon should be allowed to pump crazy money into a club with sponsorship from five companies he controls. If that happens, financial fair play will fail."
Current rules in the Bundesliga stipulate all teams must be at least 51 per cent owned by club members, meaning a third-party investor would not be allowed to take overall control of a side.
However, the significant backing of Sheikh Mansour has allowed their Champions League opponents Manchester City to become a footballing force in recent years. But despite their sudden growth, the Dortmund CEO has no interest in sanctioning such ownership.
He added: "I would not even welcome him [Mansour]. Maybe at other clubs, but what if the Sheikh, as shown by Malaga, lost interest? Then it becomes critical.
"The fact is that the Bundesliga has caught up considerably, thanks to their sound banking practices. This will eventually be expressed by [winning] results."
Of the upcoming Champions League clash between the two sides, Watzke said it will be a tight game due to the standard of players on show.
He continued: "There will not be many goals. At European level, you do not get as many opportunities as in a normal league game."
Meanwhile, BVB coach Jurgen Klopp assured that his side have devised a plan to stop their English opponents in the Champions League, despite the array of big names that they have in their ranks.
"Manchester City are really strong and are peppered with absolute superstars. However, we have a plan," Klupp told Bild.