Now 40, Van Buyten, who scored 10 goals from the centre-back position in 83 caps for the Red Devils, has had the pleasure of watching a golden generation of Belgians shine in Russia.
Having survived a last-16 scare at the hands of Japan, where Belgium came back from 2-0 down to win 3-2, Roberto Martinez's men went on to dump Brazil out of the competition after a strong group stage performance.
Having seen his compatriots do him proud up until now, Van Buyten knows that the test against France in the semi-finals will be no breeze – especially with young talent Mbappe on the field.
Speaking exclusively to Goal, 'DVB' revealed what he makes of the comparisons the teenager has drawn with Ronaldo Nazario.
“There is Ronaldo in him, but I think there's some Cristiano in there too,” Van Buyten began.
“He has the ability to accelerate, perform ahead of others and be a goalscorer – [Brazilian] Ronaldo had that but he was more of a pure goalscorer.
“Henry was a goalscorer and a worker, too – in fact, I think Mbappe is a good mix of all those players. But don't forget that he is just a kid.
“He is still progressing enormously and when you see what he can already do... he's one of the best offensive players in football.
“What's interesting is knowing that in three, four years he'll be even stronger. And in addition to that, he'll only be 22, 23 years old. He's a diamond and it's beautiful to see.
“I hope he keeps his head on his shoulders and continues his progress.”
Football matches are won by teams, not individuals for the most part, and Goal quizzed the former FCB stopper as to who he feels has the better chance on paper of making it to the final.
“I think it's more or less equal,” Van Buyten continued.
“It's not what's 'on paper' that counts. Japan, for example were 'on paper' not as good as Belgium, but led us 2-0. Finally, though, their lack of experience saw them lose 3-2.
“I think that both teams are good but they must show that on the pitch – and also have a little bit of luck.”
As for a prediction?
“Victory for Belgium, of course!” he said. “For the score? I think it'll be 2-1.”