Van Gaal had been mentioned as a replacement for Peter Bosz at BVB before they turned to Peter Stoger.
Former BVB winger Kevin Grosskreutz was unimpressed by the Dutchman's swipe.
He hit back: "We also do not say that he has made the Netherlands a small team. Borussia Dortmund is a big club. Each damn weekend there are 80,000 people in the Westfalenstadion and screaming their throats out."