Van Gaal was appointed as successor to David Moyes last month, and will take over after leading Netherlands in their FIFA World Cup campaign in Brazil.
Meulensteen spent 12 years at Old Trafford in a number of capacities, including as an assistant to Alex Ferguson, before a brief stint at Russian club Anzhi and an ill-fated spell at Fulham.
Having left Craven Cottage in February, Meulensteen is looking for a way back into the game, but confirmed it will not come as part of Van Gaal's team at United.
"I would have been keen to go back," he said. "I spent 12 years at what is a fantastic club and never left Man United because I fell out with anyone there.
"But they've chosen to appoint Louis van Gaal and he has decided to bring in his own people so that is not an option.
"Have I spoken to Van Gaal? Yes, I know that is the case - it has been confirmed to me.
"It is disappointing," he added. "When you spend 12 years at a club the size of Manchester United, working in every department - not least for five years with the first team which were the most successful in the history of the club - of course you are disappointed.
"There aren't many coaches who have spent so much time with one club as I have.
"You would think it would make sense to have some continuity. But the people who have made the decision think their decision makes sense as well so we'll see what the future brings."
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