Messi has had a record-breaking tournament, not only setting a new mark for the most games played but also shattering the goalscoring record with his eight goals at the finals in Canada, Mexico and the US, bringing his total to 21, and ominously for England, he's having a whale of a time in the process/
"Seeing him enjoying himself makes me really happy, considering everything he's been through with this jersey and everything he's had to fight for," said De Paul of his teammate, who also plays alongside him in Major League Soccer at Inter Miami.
"I think this World Cup has found him truly enjoying himself.
"Of course, we all know his mentality, how he prepares, and how he approaches every game. But I see him happy and enjoying it, and as a friend, that makes me very happy."
De Paul, 32, played in the World Cup final in Qatar four years ago, where Argentina edged France on post-match penalties, and is conscious of what it will take to get to Sunday's deciding game in New York.
"We have plenty of concerns, of course, because we're facing a great team. They have many top-class players, and I think they have a great coach as well," De Paul said of England.
"Those concerns simply keep us focused. We spend our time making sure they're under control."
But the overwhelming emotion of being so tantalisingly close to the final is excitement.
"Being just one step away from playing in another World Cup final... there's no greater motivation than that," De Paul told reporters as Argentina held their last training session.
"Everyone loves playing in a World Cup. Every match is a final; that's always how we've approached it. We're facing a team we've never played before, a powerhouse that has done very well in this World Cup, just like the other four teams still here. It's going to be a great match.
"I'm very happy and full of adrenaline. Personally, I really enjoy these kinds of matches. I'm trying to fully experience the moment without letting emotions overwhelm us. So we're putting a lot of thought into preparing for tomorrow's game, especially staying calm and level-headed."
No team since Brazil in 1962 has ever successfully defended the trophy, and De Paul is under no illusions that Argentina will have to pull out all the stops if they are to keep their title.
"We have done it in the Copa America, but I believe it's always much harder to win again after you've already won. To stay at the top for so many years isn't easy, and we've managed to do that. I'm very proud of my teammates," De Paul added.
"Yes, in the end, a World Cup and tournaments of this magnitude are decided by small details."
Follow England vs Argentina with Flashscore
FIFA World Cup 2026
The 2026 World Cup is taking place from June 11th to July 19th in the United States, Canada and Mexico. The tournament features 48 national teams and is played at 16 modern stadiums.
Match schedule and times | Group standings and knockout bracket | How to watch the World Cup | World Cup Format | Past winners of the tournament