The pair go head-to-head in the Allianz Arena 15 years after Van der Sar was part of Van Gaal's Ajax side that claimed Champions League glory at Juventus' expense.
Little could the current Bayern Munich coach have known the keeper he helped develop would stand in his way of a semi-final berth as he approaches his 40th birthday.
Going strong: Van der Sar is showing no signs of slowing down
Van Gaal's assessment of an extreme talent was not exactly the greatest compliment and neither is it likely to win the Manchester United player's approval.
But, in using exactly the same phrase as Sir Alex Ferguson once used to describe David Beckham, Van Gaal insists he is correct.
'I always say Van der Sar is a manufactured goalkeeper,' said Van Gaal. 'He is not so happy when I say it, but there are more natural goalkeepers in the world.
'Van der Sar has been made into a goalkeeper. It is my philosophy to train the brain and that is the reason why Van der Sar has been around so long.
'He always works with his brain. That is his secret. He is a great role model for goalkeepers around the world.'
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