"You can't smell football in here," he told me with a lip-curling look of distaste that could not have been bettered by Pacino playing Shylock. We sat deep in the bowels of the glamorous, futuristic stadium to which his great club had recently moved in 1996, and inside of which he looked like a sad exile yearning for the unattainable past.
"Ajax play tonight, then next up in here is Tina Turner," he said, almost mockingly, as if trying to suggest that his club had been reduced to performing in a grubby vaudeville theatre that might even have belly-dancers next on the bill. He obviously had been led screaming and kicking from his beloved Wooden Stadium, as it was called, to this strange edifice that looked from afar like a prop from Close Encounters of the Third Kind, because he feared that their new vulnerable status as tenants, even with increased attendances, would impair the great traditions of the past. The absence of the aromas of the boot-room seemed to disturb him. He was prescient in that regard.
But as he sat in the stand at Celtic Park two weeks ago, watching as Dutch national coach, there can be little doubt he was doing so with as much affection for the red and white shirts as in the past. For he still remains the great traditionalist and theologian of Ajax values that he laid out to me like someone reciting a catechism.
"When a kid first walks through the Ajax door he will play within exactly the same structure all the way through his career until he can walk into the first team with an instinctive understanding of what we are about," he said. "They know how we play at the back. It never alters. They learn about individual responsibility within the system but the structure remains. They could play blindfold eventually and still know what's happening around them. This is our way."
Their way. That is all he needed to say and in the mind's eye you could picture Cruyff and Neeskens and Rensenbrink et al, in different generations, cavorting about the pitch in those flowing movements that was the full flowering of "total football" as it had been tagged. We could argue that other great teams in the past - such as the Celtic side who triumphed in Lisbon with a full-back on one side, Tommy Gemmell, scoring a crucial goal and another, Jim Craig, laying it on for him, and a wee winger called Jinky running all over the pitch - proved that the Dutch had no claim on the exclusivity of such a brand. But let us not begrudge them the fact that they greatly altered our perception of how football could be played inventively.
And who could argue then that the rest of the world envied and craved to follow? In our country we became almost besotted with pursuing the Dutch way of nurturing talent. There is a lot still to be said for that as long as it is accompanied by an occasional hard look at the realities of a fickle world.
Celtic Park offered the perfect opportunity to do so. The young Ajax team certainly played as if they wished to honour the traditions as espoused by Van Gaal. It did not pay off for them, of course, but not by an unbridgeable gap, since they hogged a lot of the ball. But the fact they had six players in their side whom they had developed through their youth system, to Celtic's one - James Forrest - was not just because of the long-term attributes of their system, but because of necessity. The same club had departed from their traditions and catastrophically entered the transfer market with such financial clumsiness in the last decade that it would disqualify them from holding a stall at the Glasgow Barras. Even with a listing on their stock exchange the funds evaporated, making young players juicy assets and difficult to hold under the Bosman ruling.
In that real world the absolute Ajax purity could not be sustained. However, since it was highly unlikely Celtic could have fielded another five young players to accompany Forrest and get through the night successfully, the system at Ajax is still far more robust than anything we can offer at that highest level of football. For Celtic there is no other choice than to be a buying and selling club, an admission that their indigenous young talent simply is not good enough.
The need to stay in European football as long as they can is the crucial prerequisite for them sustaining their present status. If they have to recruit from Outer Mongolia, so be it. That, sadly, would be the course for any of our clubs with European ambitions. Like Ajax themselves they cannot prosper solely on domestic revenue, nor by their television deals which are like bread-queue handouts compared to those of the larger nations.
So the pressures heaped upon these two clubs are greater than on the other occasions I have been privileged to watch them compete. It will produce an atmosphere inside the Amsterdam Arena that might make Van Gaal forget that Tina Turner ever dared set foot inside it.