Star striker Haaland could reportedly be allowed to depart if Dortmund receive a nine-figure sum of money in the upcoming transfer window, although he would be available for a considerably lower price of £68m next summer due to his release clause.
The situation is similar with Sancho, as Dortmund risk losing their much-coveted duo if they fail to qualify for the Champions League, but Watzke believes that the 'darker clouds' gathering over European football would make big-money moves near impossible to finance.
Speaking to Sky Deutschland, the Dortmund chief said: "Overall, I don't think that crazy things will happen. I know the situation in the European leagues very well, and the clouds are getting darker instead of lighter."
However, Watzke did concede that the financial powerhouses could still find a way to bolster their squads with world-class players, adding: "[PSG and Man City] are backed by entire states which find ways and means to pump money in."
Haaland's brace in Saturday's Klassiker defeat to Bayern Munich took him up to 19 goals for the Bundesliga season, while Sancho boasts six strikes and 11 assists in the current top-flight campaign, although he missed out at the weekend due to a muscular injury.