"He's one of the few people around who tell things straight to your face," Riquelme once said of his encounter with the Dutchman, who has led Bayern to within touching distance of a unique Bundesliga, Cup and Champions League Cup treble.
"On the first day, he sat down with me at a table, he told me that the president had signed me and not him and that he hadn't asked for me, so it was immediately obvious to me that I wasn't going to play.
"But I prefer people who are like this. The man was very sincere and I learned from the experience."
Van Gaal, whose Bayern team effectively wrapped up the Bundesliga title on Saturday with a 3-1 win over VfL Bochum, is one of the sport's most colourful coaches - sometimes literally, as he loses his temper during interviews and his face goes progressively redder with rage.
He was involved in a memorable exchange at Barcelona, telling one reporter "you are really bad" over reports that he had broken a dressing room door during a row with Brazilian playmaker Rivaldo.
Riquelme and Rivaldo, who both found themselves out of favour during Van Gaal's tumultuous three-year stint at Barcelona in the late 1990s, are among two top players whose talents Van Gaal has failed to appreciate and Italian World Cup winner Luca Toni joined the list at Bayern this year.
"For me this is a very big achievement," he said after Saturday's game. "I don't think many coaches in Europe have had the luck to be champions in three countries, I'm one of the few, I've done it in very good football countries and I'm very proud.
"May be now I should look for another country."
"I think the credit must go to my assistants. I am the coach and the players make themselves," he said.
"Bayern Munich is the best club I haved worked at in terms of organisation," said Van Gaal. "We have some great possibilities here."
