The experienced coach, who introduced the likes of Xavi, Andres Iniesta and Thomas Muller to their respective first teams, admits he is thrilled with their impressive careers
Andres Iniesta and Xavi made their full debuts under Van Gaal during his time at the Catalans, while the Dutchman promoted Thomas Muller and David Alaba to the first team while he was in charge of Bayern.
"When I see Barcelona playing with four of my players, and Bayern Munich as well, it makes me happy and proud. But the Xavis, Iniestas, Mottas, Mullers or Alabas fitted in the profile of the position," Van Gaal told the official Fifa website.
"For example, I talked with Alaba about the left full-back position. He didn’t want to play there. He was educated as a midfielder, but I had a vacant position for him because I had injuries and thought he could do the job. After a lot of talking, in the end, he played there because he wanted to help the team. Where is he playing now? Left full-back!"
Van Gaal then went on to highlight the importance of Bayern assistant coach Hermann Gerland to the Bavarians' recent success in Germany and on the continent.
"When I go to a new club, I always want to keep one coach from the existing staff and that person was Hermann Gerland, who is still working under Pep Guardiola. I wanted to know who was coming through the youth system – and he is the man who said to me: 'Muller, Badstuber and Alaba. These are the players.'
"So I let them train with the first team, I observed them – and then I decided where they were going to play. Also, Badstuber was originally a left-back and I put him as a left central defender."
Van Gaal won two La Liga titles and a Copa del Rey during his time at Barca, while guiding Bayern to the domestic double in 2009-10.