Ferguson spent a trophy-laden 27 years in charge at Old Trafford before successor David Moyes lasted just 10 months in the job as United headed for a seventh-placed finish in the Premier League last term - their lowest in the competition's history.
Ferguson has remained a regular at United in his roles as director and club ambassador, but has not yet at the chance to meet the latest man to lead the club.
Van Gaal told reporters on Friday: "No, until this moment I have not found the time to do that [meet with Ferguson] but I do not know if he is at home.
"It was in the planning that I would see him in the US [during pre-season tour] but he called off and I have also been very busy with a lot of things."
Manchester United begin the new season with a home fixture against Swansea City on Saturday.
