Mbappe’s was one of the biggest transfer sagas of the summer as a host of European clubs tried to sign the France international.
Barcelona, Real Madrid and Manchester City were linked with the 18-year-old, who helped Monaco win the Ligue 1 title last season.
He eventually moved to PSG on transfer deadline day in an initial loan move that will turn into a £168million permanent deal next summer.
That agreement was to offset PSG’s spending over two years after they splashed £200m on Neymar.
And former Barca striker Henry admits he expected Mbappe to head to Spain.
“I thought Mbappe would go to Real Madrid or Barca if he moved this summer,” Henry told the Sun on Sunday.
“But when you see the money being offered (by PSG) I was less surprised!
“I guess it also helps that he’s gone back to Paris, his home city.
“But wherever he is, he has to perform. Now. You used to have three or four years to reach the top after you showed talent. Now the expectation is instant.
“Neymar and Mbappe joining PSG is great for the French League. It will raise the profile massively.
“When I was in New York, people wore PSG shirts because of Zlatan Ibrahimovic. Now the focus will rise dramatically. PSG will be back on the map.
“There will be a lot of pressure, though, because they have joined the group of teams who are judged on whether they win the Champions League.”
Mbappe and Neymar helped PSG to a crushing 5-1 win over Mets on Friday night.
The club are already top of Ligue 1 after winning all five of their matches at the start of the season, scoring 19 goals and conceding just three.
As for Monaco, they sit second after they lost 4-0 to Nice yesterday.