Manchester United defender Lisandro Martínez said the Argentina national team doesn't consider the 2024 Copa América to be Lionel Messi's last tournament with La Albiceleste, adding that the captain remains the world's best player.

Messi has said it will be difficult for him to play at the 2026 World Cup, when he will turn 39, though coach Lionel Scaloni has voiced belief that the eight time Ballon d'Or winner can make it to the tournament in the United States, Canada and Mexico.

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"He's very calm, more than anything he's enjoying the day to day. It's beautiful to be here, we all have a great relationship," Martínez said in a media availability Thursday, during the team's preparations in Fort Lauderdale, Florida.

"When one is here, one is very happy. We feel at home, which is important. We don't see it [as his last tournament with Argentina.] We see him happy, and with an impressive level. That's what I can tell you."

Messi has been an integral part of the Argentinian national team's recent success, captaining the side to win the 2021 Copa América and 2022 FIFA World Cup. Since his debut in 2005, the forward has scored 106 goals in 180 international appearances to become the country's all-time top scorer.

The former Barcelona and Paris Saint-Germain star remains in fine form, scoring 11 goals and adding 12 assists in 12 games for Inter Miami CF in MLS this season. His contract with Miami runs through the end of the 2025 season.

"Playing with Leo, for us it's a very important plus," Martínez added. "Everyone knows what Leo represents, he's the best in the world. Having him play for our team is without a doubt a plus. We are very happy to share the day to day with him."

Argentina will face Ecuador and Guatemala in friendlies to prepare for the upcoming Copa América. The event is being hosted in the U.S., with four teams from Concacaf -- including the hosts -- joining 10 from South America.

"Copa América is a complicated tournament," Martínez said. "Without a doubt, everyone wants to beat us because we're the reigning champions.

"But if we go into it thinking of a couple 'favorites' or 'strong teams' we're only hurting ourselves. We know what we represent, so every game for us is a final.

"Our expectation is to win Copa América."

Martínez maintains that the team is focused and training at an "impressive" level that leads him to believe Argentina can once again lift the coveted trophy.

"Without a doubt, everyone wants to beat us," he said. "But we're ready for that and work hard for that. We have a great team, with players that are incredible. When training, it's incredible to see the talent and effort being put in. We're ready."

Argentina kick off their Copa América campaign on June 20 when facing Canada in the inaugural match at Mercedes-Benz Stadium in Atlanta.