Louis van Gaal claims he rejected a chance to take over as Bayern Leverkusen boss and would only return to top-flight coaching in charge of a "big club" – a list that does not include Borussia Dortmund.
Speaking to Dutch television programme De Tafel van Kees on Fox Sports, the 66-year-old explained he had set a particularly high bar on any footballing return.
"I had an offer from Bayer Leverkusen, which is a club tailored for me, with many young talents," he said, before immediately adding the approach was turned down.
Dortmund swiftly appointed Peter Stoger to succeed Van Gaal's ailing countryman Peter Bosz this weekend, a job that did not interest the veteran.
"I think Dortmund is not comparable to Bayern Munich, so no," he added.
"Nowadays, as a coach, you do not have that much time, so I cannot change enough to turn a small club into a big club."
Elsewhere in the interview, Van Gaal criticised United successor Jose Mourinho for playing defensive football at Old Trafford – a charge that played a significant part in his own downfall with the 20-time English champions.