Messi signed for PSG as a free agent after being let go by Barca, and much was expected from the Argentine as he would be paired alongside Kylian Mbappe and Neymar. But his move has failed to inspire PSG's attack at times this season.
Henry, who played alongside Messi at Barcelona, outlined a few clear reasons why his former teammate has struggled to find his feet in France.
"Without wanting to make excuses for Mauricio Pochettino, when so many players arrive late [for the start of the season], you don't have time to work with them when you're playing every three days," the former Arsenal hero told Le Journal du Dimanche (via The Mirror).
"They are going off on international duty whenever you might have the time, it's not easy to find a style of play. At Barcelona, you have to follow something because there's a history. Rinus Michels was there, then Cruyff came along... Pochettino is looking for a system and 11 players to play in it."
PSG added a number of players on free transfers in the summer, including Gianluigi Donnarumma, Sergio Ramos, and Gini Wijnaldum. Mauricio Pochettino recently spoke glowingly about his current situation at the Parc des Princes however, insisting he cannot work with a higher calibre of player.
He said: "Now we are talking about Neymar, Mbappé, Messi… you cannot go higher than this level of player."