De Boer played for Van Gaal throughout his career.
"I think you are getting one of the best managers in the world so the chance of success is high," he told MUTV. "I believe that, especially when you have patience, because he will get success because he's so determined to do well but also he has a great vision.
"On his tactics, he will know the weak points of the opponents, and what the team needs, so he can really make a very strong team and a team that believes in each other. Sometimes it takes time to get that belief from the players, some will not accept that and will drop off, but when you have everybody together, believe me, you will have great success. I've seen so many coaches and he stands out so far ahead."
For the big stories and the banter follow us on Twitter: @tribalfootball